Exhibit 99.1

Press Release, 7 August 2019

Interxion Reports Second Quarter 2019 Results

Revenue Growth of 14% Year Over Year

Demand Drives New Investments in Frankfurt, Paris, Marseille and Stockholm

AMSTERDAM 7 August 2019 – Interxion Holding NV (NYSE: INXN), a leading European provider of carrier and cloud-neutral colocation data centre services, today announced its results for the three-month period ended 30 June 2019 and further investments in four markets.

Financial Highlights

• Revenue increased by 14% to €158.5 million (2Q 2018: €138.8 million).

• Recurring revenue⁽¹⁾ increased by 14% to €150.0 million (2Q 2018: €131.7 million).

• Net income increased by €8.0 million to €8.6 million (2Q 2018: €0.6 million).

• Adjusted net income⁽¹⁾ decreased by 16% to €7.5 million (2Q 2018: €8.9 million).

• Diluted earnings per share increased by €0.11 to €0.12 (2Q 2018: €0.01).

• Adjusted diluted earnings per share⁽¹⁾ decreased by 16% to €0.10 (2Q 2018: €0.12).

• Adjusted EBITDA⁽¹⁾ increased by 26% to €80.2 million (2Q 2018: €63.4 million).

• Adjusted EBITDA margin⁽¹⁾ increased to 50.6% (2Q 2018: 45.7%).

• Capital expenditure, including intangible assets⁽²⁾, were €123.5 million (2Q 2018: €120.5 million).

¹  All of the following items are non-IFRS measures intended to adjust for certain items and are not measures of financial performance under IFRS: “Adjusted EBITDA”, “Adjusted EBITDA margin”, “Adjusted EBITDA excluding the impact of IFRS 16”, “Adjusted EBITDA margin excluding the impact of IFRS 16”, “Recurring revenue”, “Revenue on a constant currency basis”, “Adjusted net income”, “Adjusted basic earnings per share”, “Adjusted diluted earnings per share” and “Cash generated from operations”. Complete definitions can be found in the “Non-IFRS Financial Measures” section in this press release. Reconciliations of Net income to Adjusted EBITDA, Adjusted EBITDA to Adjusted EBITDA excluding the impact of IFRS 16, Net income to Adjusted net income and Revenue to Recurring revenue, can be found in the financial tables later in this press release.

²  Capital expenditure, including intangible assets, represents payments to acquire property, plant and equipment and intangible assets, as recorded in the consolidated statement of cash flows as “Purchase of property, plant and equipment” and “Purchase of intangible assets”, respectively.

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Operating Highlights

• Equipped space⁽³⁾ increased by 6,500 square metres (“sqm”) during the quarter to 154,800 sqm metres.

• Revenue generating space⁽⁴⁾ increased by 2,600 sqm during the quarter to 121,600 sqm.

• Utilisation rate⁽⁵⁾ at the end of the quarter was 79%.

• During the second quarter, Interxion completed the following capacity additions:

• 2,000 sqm in Vienna;

• 1,300 sqm in Madrid;

• 1,100 sqm in Marseille;

• 800 sqm in Stockholm;

• 600 sqm in London;

• 400 sqm in Paris; and

• 300 sqm in Dusseldorf.

³  Equipped space is the amount of data centre space that, on the date indicated, is equipped and either sold or could be sold, without making any significant additional investments to common infrastructure.

⁴  Revenue generating space is the amount of Equipped space that is under contract and billed on the date indicated.

⁵  Utilisation rate represents Revenue generating space as a percentage of Equipped space.

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“As reflected in the solid second quarter results, Interxion continues to experience favourable demand, driven primarily by the cloud and content platform providers,” said David Ruberg, Interxion’s Chief Executive Officer. “In response to customer demand and orders, we are announcing today incremental investments in Frankfurt, Paris, Marseille and Stockholm. Our recent equity issuance and credit rating upgrade support our ongoing expansion activity, with a focus on sustaining our attractive returns.”

Quarterly Review

As previously noted, the implementation of International Financial Reporting Standard 16 - Leases (“IFRS 16”) on 1 January 2019 reclassified certain expense items, thus impacting the comparability of our results to periods prior to the implementation of IFRS 16. This accounting change had no impact on our revenues or underlying net cash flows. A reconciliation from Adjusted EBITDA and Adjusted EBITDA margin reported after giving effect to IFRS 16 to corresponding measures excluding the impact of IFRS 16 are provided later in this press release.

Revenue in the second quarter of 2019 was €158.5 million, a 14% increase over the second quarter of 2018 and a 5% increase over the first quarter of 2019. Recurring revenue was €150.0 million, a 14% increase over the second quarter of 2018 and a 3% increase over the first quarter of 2019. Recurring revenue in the second quarter represented 95% of total revenue. On a constant currency⁽⁶⁾ basis, revenue in the second quarter of 2019 was 14% higher than in the second quarter of 2018.

Cost of sales in the second quarter of 2019 was €54.7 million, a 2% increase over the second quarter of 2018 and a 9% increase over the first quarter of 2019.

Gross profit was €103.7 million in the second quarter of 2019, a 22% increase over the second quarter of 2018 and a 3% increase over the first quarter of 2019. Gross profit margin was 65.5% in the second quarter of 2019, compared with 61.3% in the second quarter of 2018 and 66.7% in the first quarter of 2019.

⁶  We present constant currency information to assess how our underlying businesses performed excluding the effect of foreign currency rate fluctuations. To present this information, current and comparative prior period results for entities reporting in currencies other than Euro are converted into Euro using the average exchange rates from the prior period rather than the actual exchange rates in effect during the current period.

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Sales and marketing costs in the second quarter of 2019 were €9.4 million, a 2% decrease over the second quarter of 2018 and a 3% increase over the first quarter of 2019.

General and administrative costs, excluding the items we adjust for in the determination of Adjusted EBITDA, were €14.2 million in the second quarter of 2019, a 17% increase over the second quarter of 2018 and a 4% decrease from the first quarter of 2019.

Depreciation and amortisation in the second quarter of 2019 were €44.3 million, a 38% increase over the second quarter of 2018 and a 6% increase over the first quarter of 2019.

Operating income in the second quarter of 2019 was €29.6 million, an increase of 12% over the second quarter of 2018 and a 1% decrease from the first quarter of 2019.

Net finance expense for the second quarter of 2019 was €17.1 million, a 25% decrease from the second quarter of 2018 and a 3% increase over the first quarter of 2019.

Income tax expense for the second quarter of 2019 was €3.6 million, a 30% increase over the second quarter of 2018 and a 24% decrease from the first quarter of 2019.

Net income was €8.6 million in the second quarter of 2019, an €8.0 million increase over the second quarter of 2018 and a 3% increase from the first quarter of 2019.

Adjusted net income was €7.5 million in the second quarter of 2019, a 16% decrease from the second quarter of 2018 and a 6% increase from the first quarter of 2019.

Adjusted EBITDA for the second quarter of 2019 was €80.2 million, a 26% increase over the second quarter of 2018 and a 4% increase over the first quarter of 2019. Adjusted EBITDA margin was 50.6% in the second quarter of 2019 compared to 45.7% in the second quarter of 2018 and 51.0% in the first quarter of 2019.

Adjusted EBITDA excluding the effects of IFRS 16 for the second quarter was €71.5 million, a 13% increase over the second quarter of 2018 and a 3% increase over the first quarter of 2019. Adjusted EBITDA margin excluding the effects of IFRS 16 in the second quarter of 2019, was 45.1%, compared to 45.7% in the second quarter of 2018 and 45.7% in the first quarter of 2019.

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Net cash flows from operating activities in the second quarter of 2019 were €35.8 million compared to €31.6 million in the second quarter of 2018 and €71.3 million in the first quarter of 2019.

Cash generated from operations⁽¹⁾ in the second quarter of 2019 was €71.8 million compared to €55.1 million in the second quarter of 2018 and €79.9 million in the first quarter of 2019.

Capital expenditure, including intangible assets, in the second quarter of 2019 were €123.5 million compared with €120.5 million in the second quarter of 2018 and €144.1 million in the first quarter of 2019.

Cash and cash equivalents were €55.6 million at 30 June 2019, compared with €186.1 million at year end 2018.

Total borrowings and lease liabilities net of cash and cash equivalents were €1,672.2 million in aggregate at 30 June 2019, compared with €1,104.1 million at 31 December 2018. Excluding lease liabilities, total borrowings were €1,276.7 million at 30 June 2019, compared with €1,239.8 million at 31 December 2018.

As at 30 June 2019, €40 million was drawn under Interxion’s €300 million unsecured revolving credit facility. The full amount was repaid after the end of the quarter.

On 1 July 2019, Interxion issued 4.6 million ordinary shares in a public offering generating net proceeds of €283.2 million.

Equipped space at the end of the second quarter of 2019 was 154,800 square metres, compared to 132,600 square metres at the end of the second quarter of 2018 and 148,300 square metres at the end of the first quarter of 2019. Revenue generating space at the end of the second quarter of 2019 was 121,600 square metres, compared to 106,200 square metres at the end of the second quarter of 2018 and 119,000 square metres at the end of the first quarter of 2019. Utilisation rate, the ratio of revenue

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generating space to equipped space, was 79% at the end of the second quarter of 2019, compared to 80% at the end of the second quarter of 2018 and 80% at the end of the first quarter of 2019.

Investment Initiatives in Frankfurt, Marseille, Stockholm and Paris

In response to continued customer demand and orders, Interxion will expand existing data centres in Frankfurt and Marseille and construct a new data centre in Stockholm (“STO6”). Additionally, Interxion has added to its land ownership in Paris.

In Frankfurt, Interxion will add capacity in its FRA15 data centre by constructing Phases 3 and 4. These phases will add an additional 4,700 square metres of equipped space and are scheduled to open in 3Q 2021. The capital expenditure associated with the final two phases of FRA15 is expected to be approximately €40 million.

In Marseille, Interxion will construct the second phase of its MRS3 data centre. This phase will provide approximately 2,400 sqm of equipped space and is scheduled to open in 3Q 2020. The capital expenditure associated with this phase of MRS3 is expected to be approximately €31 million.

In Stockholm, STO6 will be constructed in four phases, delivering a total of 3,300 sqm of equipped space and 5 megawatts (“MW”) of customer available power when fully built out. The first phase of STO6, which is expected to provide approximately 500 sqm, is scheduled to open in 2Q 2020. The second phase is expected to provide approximately 600 sqm and is scheduled to open in 4Q 2020. The capital expenditure associated with the first two phases of STO6 is expected to be approximately €21 million.

In Paris, Interxion completed the acquisition of the land on which its PAR7 data centre is located, for €19 million. The PAR7 site is adjacent to additional land of 68,000 sqm, over which we have a purchase option. This site has an industrial zoning rating and access to 50 MW of available power.

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Business Outlook

Interxion today is reaffirming guidance for Revenue, Adjusted EBITDA and Capital expenditure (including intangibles) for full year 2019:

Revenue	€632 million – €647 million
Adjusted EBITDA	€324 million – €334 million
Capital expenditure (including intangibles)	€570 million – €600 million

Conference Call to Discuss Results

Interxion will host a conference call today at 8:30 a.m. ET (1:30 p.m. BST, 2:30 p.m. CET) to discuss the results.

To participate on this call, U.S. callers may dial toll free 1-866-966-1396; callers outside the U.S. may dial direct +44 (0) 2071 928 000. The conference ID for this call is INXN. This event also will be webcast live over the Internet in listen-only mode at investors.interxion.com.

A replay of this call will be available shortly after the call concludes and will be available until 21 August 2019. To access the replay, U.S. callers may dial toll free 1-866-331-1332; callers outside the U.S. may dial direct +44 (0) 3333 009 785. The replay access number is 3364477.

Forward-looking Statements

This communication contains forward-looking statements that involve risks and uncertainties. There can be no assurance that such statements will prove to be accurate and actual results and future events could differ materially from those anticipated in such forward-looking statements. Factors that could cause actual results and future events to differ materially from Interxion’s expectations include, but are not limited to, the difficulty of reducing operating expenses in the short term, the inability to utilise the

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capacity of newly planned data centres and data centre expansions, significant competition, the cost and supply of electrical power, data centre industry over-capacity, performance under service level agreements, delays in remediating the material weakness in internal control over financial reporting and/or making disclosure controls and procedures effective, certain other risks detailed herein and other risks described from time to time in Interxion’s filings with the United States Securities and Exchange Commission (the “SEC”).

Interxion does not assume any obligation to update the forward-looking information contained in this press release.

Non-IFRS Financial Measures

These materials include non-IFRS financial measures and ratios, including (i) Adjusted EBITDA; (ii) Adjusted EBITDA margin, (iii) Adjusted EBITDA excluding the impact of IFRS 16; (iv) Adjusted EBITDA margin excluding the impact of IFRS 16; (v) Recurring revenue; (vi) Revenue on a constant currency basis; (vii) Adjusted net income; (viii) Adjusted basic earnings per share; (ix) Adjusted diluted earnings per share and (x) Cash generated from operations, that are not required by, or presented in accordance with, IFRS.

Other companies may present Adjusted EBITDA, Adjusted EBITDA margin, Adjusted EBITDA excluding the impact of IFRS 16, Adjusted EBITDA margin excluding the impact of IFRS 16, Recurring revenue, Revenue on a constant currency basis, Adjusted net income, Adjusted basic earnings per share, Adjusted diluted earnings per share and Cash generated from operations differently than we do. None of these measures are measures of financial performance under IFRS and should not be considered as a measure of liquidity or as an alternative to Profit for the period attributable to shareholders (“Net income”) or as indicators of our operating performance or any other measure of performance implemented in accordance with IFRS.

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Adjusted EBITDA, Adjusted EBITDA margin, Adjusted EBITDA excluding the impact of IFRS 16, Adjusted EBITDA margin excluding the impact of IFRS 16, Recurring revenue and Revenue on a constant currency basis

We define Adjusted EBITDA as Net income adjusted for income tax expense, net finance expense and the following items, which may occur in any period, and which management believes are not representative of our operating performance:

• Depreciation and amortisation – property, plant and equipment and intangible assets (except goodwill) are depreciated and amortised on a straight-line basis over the estimated useful life. We believe that these costs do not represent our operating performance.

• Share-based payments – represents primarily the fair value at the date of grant of employee equity awards, which is recognized as an expense over the vesting period. In certain cases, the fair value is redetermined for market conditions at each reporting date, until the final date of grant is achieved. We believe that this expense does not represent our operating performance.

• Income or expense related to the evaluation and execution of potential mergers or acquisitions (“M&A”) – under IFRS, gains and losses associated with M&A activity are recognized in the period in which such gains or losses are incurred. We exclude these effects because we believe they are not reflective of our ongoing operating performance.

• Adjustments related to terminated and unused data centre sites – these gains and losses relate to historical leases entered into for certain brownfield sites, with the intention of developing data centres, which were never developed, and for which management has no intention of developing into data centres. We believe the impact of gains and losses related to unused data centres is not reflective of our business activities and our ongoing operating performance.

In certain circumstances, we may also adjust for other items that management believes are not representative of our current ongoing performance. Examples include: adjustments for the cumulative effect of a change in accounting principle or estimate, impairment losses, litigation gains and losses or windfall gains and losses. Adjusted EBITDA margin is defined as Adjusted EBITDA as a percentage of revenue.

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In addition, we present Adjusted EBITDA excluding the impact of IFRS 16 for comparative purposes with regard to Adjusted EBITDA presented in periods prior to 1 January 2019, the effective date of IFRS 16. Adjusted EBITDA margin excluding the impact of IFRS 16 is defined as Adjusted EBITDA excluding the impact of IFRS 16 as a percentage of revenue.

For a reconciliation of Net income to Adjusted EBITDA and from Adjusted EBITDA to Adjusted EBITDA excluding the impact of IFRS 16, see the notes to the Condensed Consolidated Interim Financial Statements. Adjusted EBITDA, Adjusted EBITDA margin, Adjusted EBITDA excluding the impact of IFRS 16, Adjusted EBITDA margin excluding the impact of IFRS 16 and other key performance indicators may not be indicative of our historical results of operations based on IFRS, nor are they meant to be predictive of future results under IFRS.

We define Recurring revenue as revenue incurred from colocation and associated power charges, office space, amortised set-up fees, cross-connects and certain recurring managed services (but excluding any ad hoc managed services) provided by us directly or through third parties, excluding rents received for the sublease of unused sites. Management believes that the exclusion of these items provides useful supplemental information to revenue from colocation and associated power charges to aid investors in evaluating the recurring revenue performance of our business. For a reconciliation of Revenue to Recurring revenue, see the notes to the Condensed Consolidated Interim Financial Statements.

We present constant currency information for revenue to provide a framework for assessing how our underlying businesses performed excluding the effect of foreign currency rate fluctuations. To present this information, current and comparative prior period results for entities reporting in currencies other than Euro are converted into Euro using the average exchange rates from the prior period rather than the actual exchange rates in effect during the current period. We believe that revenue growth is a key indicator of how a company is progressing from period to period and presenting constant currency information for revenue provides useful supplemental information to investors regarding our on-going operational performance because it helps us and our investors evaluate the on-going operating performance of the business after removing the impact of currency exchange rates.

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We believe Adjusted EBITDA, Adjusted EBITDA margin, Adjusted EBITDA excluding the impact of IFRS 16, Adjusted EBITDA margin excluding the impact of IFRS 16, Recurring revenue and Revenue on a constant currency basis provide useful supplemental information to investors regarding our ongoing operational performance. These measures help us and our investors evaluate the ongoing operating performance of the business after removing the impact of our capital structure (primarily interest expense), our asset base (primarily depreciation and amortisation) and the implementation of new accounting standards. Management believes that the presentation of Adjusted EBITDA and Adjusted EBITDA excluding the impact of IFRS 16, when combined with the primary IFRS presentation of Net income, provides a more complete analysis of our operating performance. Management also believes the use of Adjusted EBITDA and Adjusted EBITDA excluding the impact of IFRS 16 facilitates comparisons between us and other data centre operators (including other data centre operators that are REITs) and other infrastructure-based businesses. Adjusted EBITDA excluding the impact of IFRS 16 is also a relevant measure used in the financial covenants of our revolving credit facility and our 4.75% Senior Notes due 2025. Pursuant to the terms of our revolving credit facility and our 4.75% Senior Notes due 2025, the calculation of Adjusted EBITDA for the purposes of the financial covenants is determined in accordance with IFRS as of the date of the financing agreements and therefore does not include the impact of IFRS 16.

Adjusted net income, Adjusted basic earnings per share and Adjusted diluted earnings per share

We define Adjusted net income as Net income adjusted for the following items and the related income tax effect, which may occur in any period, and which management believes are not reflective of our operating performance:

• Income or expense related to the evaluation and execution of potential mergers or acquisitions (“M&A”) – under IFRS, gains and losses associated with M&A activity are recognized in the period in which such gains or losses are incurred. We exclude these effects because we believe they are not reflective of our ongoing operating performance.

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• Adjustments related to provisions – these adjustments are made for adjustments in provisions that are not reflective of the ongoing operating performance of Interxion. These adjustments may include changes in provisions for onerous lease contracts.

• Adjustments related to capitalized interest – under IFRS, we are required to calculate and capitalize interest allocated to the investment in data centres and exclude it from Net income. We believe that reversing the impact of capitalized interest provides information about the impact of the total interest costs and facilitates comparisons with other data centre operators.

In certain circumstances, we may also adjust for other items that management believes are not representative of our current ongoing performance. Examples include: adjustments for the cumulative effect of a change in accounting principle or estimate, impairment losses, litigation gains and losses or windfall gains and losses.

Management believes that the exclusion of certain items listed above provides useful supplemental information to Net income to aid investors in evaluating the operating performance of our business and comparing our operating performance with other data centre operators and infrastructure companies. We believe the presentation of Adjusted net income, when combined with Net income prepared in accordance with IFRS, is beneficial to a complete understanding of our performance. A reconciliation from reported Net income to Adjusted net income is provided in notes to the Condensed Consolidated Interim Financial Statements.

Adjusted basic earnings per share and Adjusted diluted earnings per share amounts are determined on Adjusted net income.

Cash generated from operations

Cash generated from operations is defined as Net cash flows from operating activities, excluding interest and corporate income tax payments and receipts. Management believes that the exclusion of these items provides useful supplemental information to Net cash flows from operating activities to aid investors in evaluating the cash generating performance of our business.

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Additional Key Performance Indicators

In addition to Adjusted EBITDA, Adjusted EBITDA margin, Adjusted EBITDA excluding the impact of IFRS 16, Adjusted EBITDA margin excluding the impact of IFRS 16, Recurring revenue, Revenue on a constant currency basis, Adjusted net income, Adjusted basic earnings per share, Adjusted diluted earnings per share and Cash generated from operations, our management also uses the following key performance indicators as measures to evaluate our performance:

• Equipped space: the amount of data centre space that, on the date indicated, is equipped and either sold or could be sold, without making any significant additional investments to common infrastructure. Equipped space at a particular data centre may decrease if either (a) the power requirements of customers at a data centre change so that all or a portion of the remaining space can no longer be sold because the space does not have enough power capacity and/or common infrastructure to support it without further investment or (b) if the design and layout of a data centre changes to meet among others, fire regulations or customer requirements, and necessitates the introduction of common space (such as corridors) which cannot be sold to individual customers;

• Revenue generating space: the amount of Equipped space that is under contract and billed on the date indicated;

• Utilisation rate: on the date indicated, Revenue generating space as a percentage of Equipped space. Some Equipped space is not fully utilised because of customers’ specific requirements regarding the layout of their equipment. In practice, therefore, Utilisation rate does not reach 100%.

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IFRS 16 – Leases

We adopted International Financial Reporting Standard 16 – Leases, from 1 January 2019. Under IFRS 16, operating leases are recognized as right of use assets and lease liabilities, and certain components of revenue are recognized as lease revenue.

The impact of IFRS 16 on revenue, gross profit, operating income, Adjusted EBITDA, depreciation and amortisation and net finance expense for the three-month and six-month periods ended 30 June 2019 and total assets and total liabilities as at 30 June 2019 is provided in the tables attached to this press release.

-ENDS-

About Interxion

Interxion (NYSE: INXN) is a leading provider of carrier and cloud-neutral colocation data centre services in Europe, serving a wide range of customers through 53 data centres in 11 European countries. Interxion’s uniformly designed, energy efficient data centres offer customers extensive security and uptime for their mission-critical applications. With over 700 connectivity providers, 21 European Internet exchanges, and most leading cloud and digital media platforms across its footprint, Interxion has created connectivity, cloud, content and finance hubs that foster growing customer communities of interest. For more information, please visit www.interxion.com.

Contact information:

Interxion

Jim Huseby

Investor Relations

Tel: +1-813-644-9399

IR@interxion.com

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INTERXION HOLDING NV

CONDENSED CONSOLIDATED INCOME STATEMENTS

(in €‘000 — except per share data and where stated otherwise)

(unaudited)

	Three Months Ended						Six Months Ended
	Jun-30			Jun-30			Jun-30			Jun-30
	2019			2018			2019			2018
Revenue		158,476			138,824			310,007			272,660
Cost of sales		(54,729	)		(53,701	)		(105,123	)		(106,398	)
Gross Profit		103,747			85,123			204,884			166,262
Other income		—			—			—			86
Sales and marketing costs		(9,397	)		(9,601	)		(18,551	)		(18,309	)
General and administrative costs		(64,798	)		(49,250	)		(126,942	)		(94,894	)
Operating income		29,552			26,272			59,391			53,145
Net finance expense		(17,148	)		(22,895	)		(33,810	)		(34,299	)
Share of result of equity-accounted investees, net of tax		(163	)		—			(163	)		—
Profit before income taxes		12,241			3,377			25,418			18,846
Income tax expense		(3,627	)		(2,795	)		(8,405	)		(6,608	)
Net income		8,614			582			17,013			12,238
Basic earnings per share(a): (€)		0.12			0.01			0.24			0.17
Diluted earnings per share(b): (€)		0.12			0.01			0.23			0.17
Number of shares outstanding at the end of the period (shares in thousands)		71,888			71,609			71,888			71,609
Weighted average number of shares for Basic EPS (shares in thousands)		71,876			71,481			71,843			71,455
Weighted average number of shares for Diluted EPS (shares in thousands)		72,457			71,946			72,398			71,902
							As at
							Jun-30			Jun-30
Capacity metrics							2019			2018
Equipped space (in square meters)								154,800			132,600
Revenue generating space (in square meters)								121,600			106,200
Utilisation rate								79	%		80	%

(a) Basic earnings per share are calculated as net income divided by the weighted average number of shares for Basic EPS.

(b) Diluted earnings per share are calculated as net income divided by the weighted average number of shares for Diluted EPS.

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INTERXION HOLDING NV

NOTES TO CONDENSED CONSOLIDATED INCOME STATEMENTS: REPORTING SEGMENT INFORMATION

(in €‘000 — except where stated otherwise)

(unaudited)

	Three Months Ended						Six Months Ended
	Jun-30			Jun-30			Jun-30			Jun-30
	2019			2018			2019			2018
Consolidated
Recurring revenue		149,975			131,709			295,253			258,671
Non-recurring revenue		8,501			7,115			14,754			13,989
Revenue		158,476			138,824			310,007			272,660
Net income		8,614			582			17,013			12,238
Net income margin		5.4	%		0.4	%		5.5	%		4.5	%
Operating income		29,552			26,272			59,391			53,145
Operating income margin		18.6	%		18.9	%		19.2	%		19.5	%
Adjusted EBITDA		80,158			63,431			157,435			124,306
Gross profit margin		65.5	%		61.3	%		66.1	%		61.0	%
Adjusted EBITDA margin		50.6	%		45.7	%		50.8	%		45.6	%
Total assets		2,743,383			1,975,113			2,743,383			1,975,113
Total liabilities(a)		2,082,604			1,368,236			2,082,604			1,368,236
Capital expenditure, including intangible assets(b)		(123,477	)		(120,515	)		(267,558	)		(216,709	)
France, Germany, the Netherlands, and the UK
Recurring revenue		100,673			87,317			197,536			170,771
Non-recurring revenue		4,962			4,196			9,399			8,653
Revenue		105,635			91,513			206,935			179,424
Operating income		33,584			30,311			66,896			57,946
Operating income margin		31.8	%		33.1	%		32.3	%		32.3	%
Adjusted EBITDA		62,935			51,388			124,056			99,366
Gross profit margin		66.3	%		63.2	%		66.9	%		62.2	%
Adjusted EBITDA margin		59.6	%		56.2	%		59.9	%		55.4	%
Total assets		1,968,376			1,360,299			1,968,376			1,360,299
Total liabilities(a)		623,050			275,898			623,050			275,898
Capital expenditure, including intangible assets(b)		(77,780	)		(82,556	)		(177,405	)		(153,130	)
Rest of Europe
Recurring revenue		49,302			44,392			97,717			87,900
Non-recurring revenue		3,539			2,919			5,355			5,336
Revenue		52,841			47,311			103,072			93,236
Operating income		20,628			18,643			41,637			38,242
Operating income margin		39.0	%		39.4	%		40.4	%		41.0	%
Adjusted EBITDA		32,593			27,171			64,835			54,742
Gross profit margin		69.8	%		65.0	%		70.8	%		66.3	%
Adjusted EBITDA margin		61.7	%		57.4	%		62.9	%		58.7	%
Total assets		685,304			443,999			685,304			443,999
Total liabilities(a)		210,740			84,045			210,740			84,045
Capital expenditure, including intangible assets(b)		(37,891	)		(29,805	)		(79,476	)		(52,472	)
Corporate and other
Operating income		(24,660	)		(22,682	)		(49,142	)		(43,043	)
Adjusted EBITDA		(15,370	)		(15,128	)		(31,456	)		(29,802	)
Total assets		89,703			170,815			89,703			170,815
Total liabilities(a)		1,248,814			1,008,293			1,248,814			1,008,293
Capital expenditure, including intangible assets(b)		(7,806	)		(8,154	)		(10,677	)		(11,107	)

(a) Certain comparative figures as at 30 June 2018 have been restated compared to the amounts disclosed on Form 6-K furnished on 2 August 2018. For further details see Note 2 and Note 28 of our 2018 Consolidated Financial Statements included on Form 20-F, filed with the SEC on 30 April 2019.

(b) Capital expenditure, including intangible assets, represents payments to acquire property, plant and equipment and intangible assets, as recorded in the condensed consolidated statements of cash flows as “Purchase of property, plant and equipment” and “Purchase of intangible assets”, respectively.

16

Press Release, 7 August 2019

INTERXION HOLDING NV

NOTES TO CONDENSED CONSOLIDATED INCOME STATEMENTS: ADJUSTED EBITDA RECONCILIATION

(in €‘000 — except where stated otherwise)

(unaudited)

	Three Months Ended						Six Months Ended
	Jun-30			Jun-30			Jun-30			Jun-30
	2019			2018			2019			2018
Reconciliation to Adjusted EBITDA
Consolidated
Net income		8,614			582			17,013			12,238
Income tax expense		3,627			2,795			8,405			6,608
Profit before taxation		12,241			3,377			25,418			18,846
Share of result of equity-accounted investees, net of tax		163			—			163			—
Net finance expense		17,148			22,895			33,810			34,299
Operating income		29,552			26,272			59,391			53,145
Depreciation and amortisation		44,320			32,191			85,998			61,750
Share-based payments		5,725			3,927			11,405			7,249
Income or expense related to the evaluation and execution of potential mergers or acquisitions:
M&A transaction costs(a)		561			1,041			641			2,248
Items related to sub-leases on unused data centre sites(b)		—			—			—			(86	)
Adjusted EBITDA(c)		80,158			63,431			157,435			124,306
France, Germany, the Netherlands, and the UK
Operating income		33,584			30,311			66,896			57,946
Depreciation and amortisation		29,010			20,818			56,417			40,903
Share-based payments		341			259			743			603
Items related to sub-leases on unused data centre sites(b)		—			—			—			(86	)
Adjusted EBITDA(c)		62,935			51,388			124,056			99,366
Rest of Europe
Operating income		20,628			18,643			41,637			38,242
Depreciation and amortisation		11,728			8,223			22,608			15,971
Share-based payments		237			305			590			529
Adjusted EBITDA(c)		32,593			27,171			64,835			54,742
Corporate and Other
Operating loss		(24,660	)		(22,682	)		(49,142	)		(43,043	)
Depreciation and amortisation		3,582			3,150			6,973			4,876
Share-based payments		5,147			3,363			10,072			6,117
Income or expense related to the evaluation and execution of potential mergers or acquisitions:
M&A transaction costs(a)		561			1,041			641			2,248
Adjusted EBITDA(c)		(15,370	)		(15,128	)		(31,456	)		(29,802	)

(a) “M&A transaction costs” are costs associated with the evaluation, diligence and conclusion or termination of merger or acquisition activity. These costs are included in “General and administrative costs”.

(b) “Items related to sub-leases on unused data centre sites” represents the income on sub-lease of portions of unused data centre sites to third parties. This income is treated as “Other income”.

(c) “Adjusted EBITDA” is a non-IFRS financial measure. See “Non-IFRS Financial Measures” for more information, including why we believe Adjusted EBITDA is useful, and the limitations on the use of Adjusted EBITDA.

17

Press Release, 7 August 2019

INTERXION HOLDING NV

CONDENSED CONSOLIDATED BALANCE SHEET

(in €‘000 — except where stated otherwise)

(unaudited)

	As at
	Jun-30			Dec-31
	2019			2018
Non-current assets
Property, plant and equipment		1,878,533			1,721,064
Right-of-use assets		438,556			—
Intangible assets		66,492			64,331
Goodwill		38,900			38,900
Deferred tax assets		24,607			21,807
Investment in associate		3,583			—
Other investments		12,606			7,906
Other non-current assets		15,934			16,843
		2,479,211			1,870,851
Current assets
Trade receivables and other current assets		208,611			205,613
Cash and cash equivalents		55,561			186,090
		264,172			391,703
Total assets		2,743,383			2,262,554
Shareholders’ equity
Share capital		7,188			7,170
Share premium		564,592			553,425
Foreign currency translation reserve		2,965			3,541
Hedging reserve, net of tax		(179	)		(165	)
Accumulated profit		86,213			69,449
		660,779			633,420
Non-current liabilities
Borrowings		1,235,214			1,266,813
Lease liabilities		423,508			—
Deferred tax liabilities		16,912			16,875
Other non-current liabilities		17,974			34,054
		1,693,608			1,317,742
Current liabilities
Trade payables and other current liabilities		311,880			280,877
Lease liabilities		27,563			—
Income tax liabilities		8,048			7,185
Borrowings		41,505			23,330
		388,996			311,392
Total liabilities		2,082,604			1,629,134
Total liabilities and shareholders’ equity		2,743,383			2,262,554

18

Press Release, 7 August 2019

INTERXION HOLDING NV

NOTES TO THE CONDENSED CONSOLIDATED BALANCE SHEET: BORROWINGS AND LEASE LIABILITIES NET OF CASH AND CASH EQUIVALENTS

(in €‘000 — except where stated otherwise)

(unaudited)

	As at
	Jun-30		Dec-31
	2019		2018
Borrowings and lease liabilities net of cash and cash equivalents
Cash and cash equivalents		55,561		186,090
4.75% Senior Notes due 2025(a)		1,189,060		1,188,387
Finance lease liabilities (IAS 17)(b)		—		50,374
Mortgages		50,411		51,382
Borrowings under our Revolving Facilities		37,248		—
Borrowings		1,276,719		1,290,143
Lease liabilities (IFRS 16)(b)		451,071		—
Total borrowings and lease liabilities		1,727,790		1,290,143
Borrowings and lease liabilities net of cash and cash equivalents(c)		1,672,229		1,104,053

(a) The €1,200 million 4.75% Senior Notes due 2025 include a premium on additional issuances and are shown after deducting commissions, offering fees and expenses.     

(b) Under IFRS 16, finance lease liabilities are included in the aggregated amount of lease liabilities rather than presented separately.     

(c) Total borrowings and lease liabilities exclude deferred financing costs of €2.3 million as of 31 December 2018 which were incurred in connection with the €300 million Revolving Credit Facility, entered into on 18 June 2018. Total borrowings and lease liabilities include deferred financing costs of €2.7 million as of 30 June 2019. The deferred financing costs have been included as during the second quarter the Group has drawn €40.0 million under the Revolving Credit Facility.    

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Press Release, 7 August 2019

INTERXION HOLDING NV

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

(in €‘000 — except where stated otherwise)

(unaudited)

	Three Months Ended						Six Months Ended
	Jun-30 2019			Jun-30 2018			Jun-30 2019			Jun-30 2018(a)
Net income		8,614			582			17,013			12,238
Depreciation and amortisation		44,320			32,191			85,998			61,750
Share-based payments		5,395			3,646			10,501			6,863
Net finance expense		17,148			22,895			33,810			34,299
Share of result of equity-accounted investees, net of tax		163			—			163			—
Income tax expense		3,627			2,795			8,405			6,608
	79,267			62,109			155,890			121,758
Movements in trade receivables and other assets		(17,549	)		(13,858	)		(36,753	)		(20,055	)
Movements in trade payables and other liabilities		10,035			6,858			32,481			11,486
Cash generated from operations		71,753			55,109			151,618			113,189
Interest and fees paid(a)		(29,435	)		(18,600	)		(34,300	)		(38,831	)
Income tax paid		(6,529	)		(4,893	)		(10,188	)		(8,166	)
Net cash flows from operating activities		35,789			31,616			107,130			66,192
Cash flows used in investing activities
Purchase of property, plant and equipment		(119,972	)		(117,534	)		(260,667	)		(211,751	)
Financial investments - deposits		(4	)		114			12,591			280
Acquisition of associate		(3,745	)		—			(3,745	)		—
Purchase of intangible assets		(3,505	)		(2,981	)		(6,891	)		(4,958	)
Loans provided		(2,375	)		(834	)		(2,814	)		(1,251	)
Net cash flows used in investing activities		(129,601	)		(121,235	)		(261,526	)		(217,680	)
Cash flows from financing activities
Proceeds from exercised options		432			1,186			684			1,257
Repayment of mortgages		(548	)		(4,948	)		(1,020	)		(5,496	)
Proceeds from revolving credit facilities		40,000			69,376			40,000			148,814
Repayment of revolving facilities		—			(250,724	)		—			(250,724	)
Proceeds 4.75% Senior Notes		—			990,000			—			990,000
Principal elements of lease payments (2018: Financial lease obligation)		(8,356	)		—			(14,885	)		—
Repayment 6.00% Senior Secured Notes		—			(634,375	)		—			(634,375	)
Transaction costs 4.75% Senior Notes		—			(1,192	)		(200	)		(1,192	)
Transaction costs revolving credit facility		(142	)		(1,636	)		(745	)		(1,636	)
Net cash flows from financing activities		31,386			167,687			23,834			246,648
Effect of exchange rate changes on cash		(189	)		159			33			(81	)
Net increase / (decrease) in cash and cash equivalents		(62,615	)		78,227			(130,529	)		95,079
Cash and cash equivalents, beginning of period		118,176			55,336			186,090			38,484
Cash and cash equivalents, end of period		55,561			133,563			55,561			133,563

(a) Interest and fees paid is reported net of cash interest capitalized, which is reported as part of “Purchase of property, plant and equipment”.

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Press Release, 7 August 2019

INTERXION HOLDING NV

NOTES TO CONDENSED CONSOLIDATED INCOME STATEMENTS AND BALANCE SHEET: IFRS 16 IMPACT RECONCILIATION

(in €’000)

(unaudited)

	Three Months Ended									Six Months Ended
	Jun-30 2019 As Reported			Effect of change due to IFRS 16			Jun-30 2019 Excl. IFRS 16			Jun-30 2019 As Reported			Effect of change due to IFRS 16			Jun-30 2019 Excl. IFRS 16
Consolidated
Recurring revenue		149,975			—			149,975			295,253			—			295,253
Non-recurring revenue		8,501			—			8,501			14,754			—			14,754
Revenue		158,476			—			158,476			310,007			—			310,007
Gross profit		103,747			7,014			96,733			204,884			13,637			191,247
Gross profit margin		65.5	%		4.5	%		61.0	%		66.1	%		4.4	%		61.7	%
Operating income		29,552			1,265			28,287			59,391			2,799			56,593
Adjusted EBITDA		80,158			8,610			71,548			157,435			16,605			140,830
Adjusted EBITDA margin		50.6	%		5.4	%		45.1	%		50.8	%		5.4	%		45.4	%
Depreciation and amortisation		44,320			7,345			36,975			85,998			13,806			72,193
Net finance expense		17,148			3,072			14,076			33,810			6,151			27,659
France, Germany, the Netherlands, and the UK
Recurring revenue		100,673			—			100,673			197,536			—			197,536
Non-recurring revenue		4,962			—			4,962			9,399			—			9,399
Revenue		105,635			—			105,635			206,935			—			206,935
Operating income		33,584			1,130			32,454			66,896			2,271			64,625
Adjusted EBITDA		62,935			5,536			57,399			124,056			10,663			113,392
Adjusted EBITDA margin		59.6	%		5.3	%		54.3	%		59.9	%		5.1	%		54.8	%
Rest of Europe
Recurring revenue		49,302			—			49,302			97,717			—			97,717
Non-recurring revenue		3,539			—			3,539			5,355			—			5,355
Revenue		52,841			—			52,841			103,072			—			103,072
Operating income		20,628			132			20,496			41,637			508			41,128
Adjusted EBITDA		32,593			2,583			30,009			64,835			4,981			59,854
Adjusted EBITDA margin		61.7	%		4.9	%		56.8	%		62.9	%		4.8	%		58.1	%
Corporate and Other
Operating income		(24,660	)		3			(24,663	)		(49,142	)		20			(49,162	)
Adjusted EBITDA		(15,370	)		491			(15,861	)		(31,456	)		961			(32,417	)
	As at
	Jun-30 2019 As Reported			Effect of change due to IFRS 16			Jun-30 2019 Excl. IFRS 16
Consolidated
Non-current assets		2,479,211			408,447			2,070,763
Current assets		264,172			(18,551	)		282,723
Non-current liabilities		1,693,608			368,478			1,325,130
Current liabilities		388,996			23,995			365,001
France, Germany, the Netherlands, and the UK
Total assets		1,968,376			280,707			1,687,669
Total liabilities		623,050			282,618			340,433
Rest of Europe
Total assets		685,304			105,928			579,376
Total liabilities		210,740			106,586			104,154
Corporate and Other
Total assets		89,703			3,261			86,443
Total liabilities		1,248,814			3,268			1,245,546

21

Press Release, 7 August 2019

INTERXION HOLDING NV

NOTES TO CONDENSED CONSOLIDATED INCOME STATEMENTS: ADJUSTED NET INCOME RECONCILIATION

(in €‘000 — except per share data and where stated otherwise)

(unaudited)

	Three Months Ended						Six Months Ended
	Jun-30 2019			Jun-30 2018			Jun-30 2019			Jun-30 2018
Net income - as reported		8,614			582			17,013			12,238
Add back
+ Charges related to termination of financing arrangements(a)		—			11,171			—			11,171
+ M&A transaction costs		561			1,041			641			2,248
		561			12,212			641			13,419
Reverse
- Interest capitalized		(2,102	)		(1,181	)		(3,982	)		(2,065	)
	(2,102)			(1,181)			(3,982)			(2,065)
Tax effect of above add backs & reversals		385			(2,758	)		835			(2,839	)
Adjusted net income		7,458			8,855			14,507			20,753
Reported basic EPS: (€)		0.12			0.01			0.24			0.17
Reported diluted EPS: (€)		0.12			0.01			0.23			0.17
Adjusted basic EPS: (€)		0.10			0.12			0.20			0.29
Adjusted diluted EPS: (€)		0.10			0.12			0.20			0.29

(a) These charges relate to the repayment of the 6.00% Senior Secured Notes due 2020 and the termination of our revolving credit facility agreements in 2Q18.

22

Press Release, 7 August 2019

INTERXION HOLDING NV

Status of Announced Expansion Projects as at 7 August 2019

with Target Open Dates after 31 March 2019

Market	Project	CAPEX(a)(b) (€ million)		Equipped Space(a) (sqm)		Schedule
Amsterdam	AMS10: Phases 1 - 3 New Build		195		9,500	4Q 2019 - 3Q 2020(c)
Copenhagen	CPH2: Phases 3 - 5		18		1,500	2Q 2018 - 4Q 2019(d)
Dusseldorf	DUS2: Phase 3		5		500	1Q 2019 - 2Q 2019(e)
Frankfurt	FRA14: Phases 1 - 2 New Build		76		4,600	3Q 2019 - 4Q 2019(f)
Frankfurt	FRA15: Phases 1 - 4 New Build		177		9,600	2Q 2020 - 3Q 2021(g)
London	LON3: New Build		35		1,800	1Q 2019 - 3Q 2019(h)
Madrid	MAD3: New Build		44		2,700	2Q 2019 - 4Q 2019(i)
Marseille	MRS2: Phase 2 - 4		72		4,200	2Q 2018 - 4Q 2019(j)
Marseille	MRS3: Phases 1 - 2 New Build		111		4,700	1Q 2020 - 3Q 2020(k)
Paris	PAR7.2: Phase B (cont.) - C		47		2,500	2Q 2018 - 2Q 2019(l)
Stockholm	STO5: Phases 2 - 3		19		1,200	1Q 2018 - 2Q 2019(m)
Stockholm	STO6: Phase 1 - 2 New Build		21		1,100	2Q 2020 - 4Q 2020(n)
Vienna	VIE2: Phase 7 - 9		96		4,500	4Q 2017 - 4Q 2019(o)
Zurich	ZUR1: Phase 6		10		100	4Q 2019(p)
Zurich	ZUR2: Phases 1 - 2 New Build		93		3,600	3Q 2020(q)
Total			1,019		52,100

(a) CAPEX and Equipped space are approximate and may change. SQM figures are rounded to nearest 100 sqm unless otherwise noted, and totals may not add due to rounding.

(b) CAPEX reflects the total spend for the projects listed at full power and capacity and the amounts shown in the table above may be invested over time.

(c) AMS10: Phase 1 (2,700 sqm) is scheduled to open in 4Q 2019; phase 2 (4,100 sqm) is scheduled to open in 1Q 2020, phase 3 (2,700 sqm) is scheduled to open in 3Q 2020.

(d) CPH2: Phases 3 and 4 (900 sqm total) opened in 2Q 2018; phase 5 (600 sqm) is scheduled to open in 4Q 2019.

(e) DUS2: Phase 3 partially opened (300 sqm) in 1Q 2019 and the remaining 200 sqm opened in 2Q 2019.

(f) FRA14: Phase 1 (2,400 sqm) is scheduled to open in 3Q 2019; phase 2 (2,200 sqm) is scheduled to open in 4Q 2019.

(g) FRA15: Phase 1 (2,300 sqm) is scheduled to open in 2Q 2020, Phase 2 (2,600 sqm) is scheduled to open in 4Q 2020, Phase 3 (2,400 sqm) is scheduled to open in 1Q 2021 and Phase 4 (2,400 sqm) scheduled to open in 3Q 2021.

(h) LON3: Phase 1 (300 sqm) opened in 1Q 2019 and Phase 2 (600 sqm) opened in 2Q 2019. Phase 3 (900 sqm) is scheduled to open in 3Q 2019.

(i) MAD3: 1,300 sqm opened in 2Q 2019, 700 sqm is scheduled to open in 3Q 2019 and 700 sqm is scheduled to open in 4Q 2019.

(j) MRS2: Phase 2 (700 sqm) opened in 2018; Phase 3 (1,100 sqm) opened in 2Q 2019 and Phase 4 (2,500 sqm) is scheduled to open in 3Q - 4Q 2019.

(k) MRS3: Phase 1 (2,300 sqm) is scheduled to open in 1Q 2020 and Phase 2 (2,400 sqm) is scheduled to open in 3Q 2020.

(l) PAR7.2: Phase B (cont.) (500 sqm) opened in 2Q 2018; Phase C part (1,500 sqm) opened in 4Q 2018 and the remaining part (500 sqm) opened in 2Q 2019.

(m) STO5: Phases 2-3 - 100 sqm opened in 1Q 2018; 300 sqm became operational in 2Q 2018; 800 sqm opened in 2Q 2019.

(n) STO6: Phase 1 (500 sqm) is scheduled to open in 2Q 2020 and Phase 2 (600 sqm) is scheduled to open in 4Q 2020.

(o) VIE2: Phases 7-9; 2,300 sqm opened in 4Q 2017 through 3Q 2018; 2,000 sqm opened in 2Q 2019. The remaining 200 sqm is scheduled to open in 4Q 2019.

(p) ZUR1: Phase 6 (100 sqm) is scheduled to open in 4Q 2019.

(q) ZUR2: Phase 1 and Phase 2 are scheduled to open in 3Q 2020 (together 3,600 sqm).

23