Debt of the Operating Partnership

A summary of outstanding indebtedness of the Operating Partnership as of December 31, 2015 and 2014 is as follows (in thousands):



Indebtedness	Interest Rate at December 31, 2015		Maturity Date	Principal Outstanding December 31, 2015				Principal Outstanding December 31, 2014
Global revolving credit facility	Various	⁽¹⁾	Nov 3, 2017	$	967,884		⁽²⁾	$	525,951		⁽²⁾
Unsecured term loan	Various	⁽³⁾⁽⁹⁾	Apr 16, 2017	924,568			⁽⁴⁾	976,600			⁽⁴⁾
Unsecured senior notes:
Prudential Shelf Facility:
Series C	9.680%		Jan 6, 2016	25,000			⁽⁵⁾	25,000
Series D	4.570%		Jan 20, 2015	—				50,000
Series E	5.730%		Jan 20, 2017	50,000				50,000
Series F	4.500%		Feb 3, 2015	—				17,000
Total Prudential Shelf Facility				75,000				142,000
Senior Notes:
4.50% notes due 2015	4.500%		Jul 15, 2015	—				375,000
5.875% notes due 2020	5.875%		Feb 1, 2020	500,000				500,000
3.40% notes due 2020	3.400%		Oct 1, 2020	500,000				—
5.25% notes due 2021	5.250%		Mar 15, 2021	400,000				400,000
3.95% notes due 2022	3.950%		Jul 1, 2022	500,000				—
3.625% notes due 2022	3.625%		Oct 1, 2022	300,000				300,000
4.75% notes due 2023	4.750%		Oct 13, 2023	442,080			⁽¹⁰⁾	467,310			⁽¹⁰⁾
4.25% notes due 2025	4.250%		Jan 17, 2025	589,440			⁽¹⁰⁾	623,080			⁽¹⁰⁾
4.75% notes due 2025	4.750%		Oct 1, 2025	450,000				—
Unamortized discounts				(17,914		)		(15,632		)
Total senior notes, net of discount				3,663,606				2,649,758
Total unsecured senior notes, net of discount				3,738,606				2,791,758


Mortgage loans:
200 Paul Avenue 1-4 (7)	5.74%		Oct 8, 2015	—				68,665
2045 & 2055 Lafayette Street (7)	5.93%		Feb 6, 2017	61,437				62,563
34551 Ardenwood Boulevard 1-4 (7)	5.95%		Nov 11, 2016	50,477				51,339
1100 Space Park Drive (7)	5.89%		Dec 11, 2016	50,423				51,295
600 West Seventh Street	5.80%		Mar 15, 2016	46,000			⁽⁶⁾	47,825
150 South First Street (7)	6.30%		Feb 6, 2017	48,484				49,316
2334 Lundy Place (7)	5.96%		Nov 11, 2016	36,714				37,340
8025 North Interstate 35	4.09%		Mar 6, 2016	5,789			⁽⁸⁾	6,057
731 East Trade Street	8.22%		Jul 1, 2020	3,420				3,836
Unamortized net premiums				439				582
Total mortgage loans, including premiums				303,183				378,818
Total indebtedness				$	5,934,241			$	4,673,127

(1)

The interest rate for borrowings under the global revolving credit facility equals the applicable index plus a margin of 110 basis points, which is based on the credit rating of our long-term debt. An annual facility fee of 20 basis points, which is based on the credit rating of our long-term debt, is due and payable quarterly on the total commitment amount of the facility. Two six-month extensions are available, which we may exercise if certain conditions are met.


(2)	Balances as of December 31, 2015 and December 31, 2014 are as follows (balances, in thousands):



Denomination of Draw	Balance as of December 31, 2015			Weighted-average interest rate		Balance as of December 31, 2014			Weighted-average interest rate
Floating Rate Borrowing (a)
U.S. dollar ($)	$	274,000		1.46	%	$	90,000		1.27	%
British pound sterling (£)	95,784		(c)	1.61	%	132,716			1.61	%
Euro (€)	280,565		(c)	0.90	%	58,071		(d)	1.13	%
Australian dollar (AUD)	96,831		(c)	3.16	%	72,676		(d)	3.74	%
Hong Kong dollar (HKD)	86,082		(c)	1.33	%	79,336		(d)	1.34	%
Japanese yen (JPY)	14,304		(c)	1.15	%	13,201		(d)	1.17	%
Singapore dollar (SGD)	49,132		(c)	1.92	%	6,565			—
Canadian dollar (CAD)	71,186		(c)	1.95	%	62,386		(d)	2.39	%
Total	$	967,884		1.53	%	$	514,951		1.84	%
Base Rate Borrowing (b)
U.S. dollar ($)	$	—		—	%	$	11,000		3.35	%
Total borrowings	$	967,884		1.53	%	$	525,951		1.87	%


(a)	The interest rates for floating rate borrowings under the global revolving credit facility equal the applicable index plus a margin of 110 basis points, which is based on the credit rating of our long-term debt.


(b)	The interest rates for base rate borrowings under the global revolving credit facility equal the U.S. Prime Rate plus a margin of 10 basis points, which is based on the credit rating of our long-term debt.


(c)	Based on exchange rates of $1.47 to £1.00, $1.09 to €1.00, $0.73 to 1.00 AUD, $0.13 to 1.00 HKD, $0.01 to 1.00 JPY, $0.70 to 1.00 SGD and $0.72 to 1.00 CAD, respectively, as of December 31, 2015.


(d)	Based on exchange rates $1.56 to £1.00, of $1.21 to €1.00, $0.82 to 1.00 AUD, $0.13 to 1.00 HKD, $0.01 to 1.00 JPY, $0.75 to 1.00 SGD and $0.86 to 1.00 CAD, respectively, as of December 31, 2014.


(3)	Interest rates are based on our current senior unsecured debt ratings and are 120 basis points over the applicable index for floating rate advances. Two six-month extensions are available, which we may exercise if certain conditions are met.


(4)	Balances as of December 31, 2015 and December 31, 2014 are as follows (balances, in thousands):



Denomination of Draw	Balance as of December 31, 2015			Weighted-average interest rate			Balance as of December 31, 2014			Weighted-average interest rate
U.S. dollar ($)	$	410,905		1.51	%	(b)	$	410,905		1.36	%	(d)
Singapore dollar (SGD)	161,070		(a)	2.16	%	(b)	172,426		(c)	1.45	%	(d)
British pound sterling (£)	178,195		(a)	1.78	%		188,365		(c)	1.76	%
Euro (€)	99,061		(a)	1.00	%		120,375		(c)	1.22	%
Australian dollar (AUD)	75,337		(a)	3.27	%		84,529		(c)	3.98	%
Total	$	924,568		1.76	%	(b)	$	976,600		1.66	%	(d)


(a)	Based on exchange rates of $0.70 to 1.00 SGD, $1.47 to £1.00, $1.09 to €1.00 and $0.73 to 1.00 AUD, respectively, as of December 31, 2015.


(b)	As of December 31, 2015, the weighted-average interest rate reflecting interest rate swaps was 1.90% (U.S. dollar), 2.19% (Singapore dollar) and 1.94% (Total). See Note 14 for further discussion on interest rate swaps.


(c)	Based on exchange rates of $0.75 to 1.00 SGD, $1.56 to £1.00, $1.21 to €1.00 and $0.82 to 1.00 AUD, respectively, as of December 31, 2014.


(d)	As of December 31, 2014, the weighted-average interest rate reflecting interest rate swaps was 1.92% (U.S. dollar), 2.01% (Singapore dollar) and 2.00% (Total). See Note 14 for further discussion on interest rate swaps.


(5)	This note was paid in full at maturity in January 2016.


(6)	This mortgage loan was paid in full in February 2016.


(7)	The respective borrower’s assets and credit are not available to satisfy the debts and other obligations of affiliates or any other person.


(8)	This mortgage loan was paid in full in January 2016


(9)	We have entered into interest rate swap agreements as a cash flow hedge for interest generated by the U.S. dollar and Singapore dollar tranches of the unsecured term loan. See note 14 for further information.


(10)	Based on exchange rate of $1.47 to £1.00 as of December 31, 2015 and $1.56 to £1.00 as of December 31, 2014.

Global Revolving Credit Facility

On August 15, 2013, the Operating Partnership refinanced its then-existing global revolving credit facility, increasing its total borrowing capacity to $2.0 billion from $1.8 billion. The global revolving credit facility had an accordion feature that would enabled us to increase the borrowing capacity of the credit facility to $2.55 billion, subject to the receipt of lender commitments and other conditions precedent. The refinanced facility matured on November 3, 2017, with two six-month extension options available. The interest rate for borrowings under the expanded facility equaled the applicable index plus a margin which was based on the credit ratings of our long-term debt and was 110 basis points. An annual facility fee on the total commitment amount of the facility, based on the credit ratings of our long-term debt, was 20 basis points and was payable quarterly. Funds were available in U.S., Canadian, Singapore, Australian and Hong Kong dollars, as well as Euro, British pound sterling, Swiss franc, Japanese yen and Mexican peso denominations. As of December 31, 2015, interest rates were based on 1-month LIBOR, 1-month GBP LIBOR, 1-month EURIBOR, 1-month BBR, 1-month HIBOR, 1-month JPY LIBOR, 1-month SIBOR and 1-month CDOR plus a margin of 1.10%. The facility also bore a base borrowing rate of 3.35% (USD) which is based on U.S. Prime Rate plus a margin of 0.10%. We have used borrowings under the global revolving credit facility to acquire additional properties, to fund development opportunities and for general working capital and other corporate purposes. As of December 31, 2015, we have capitalized approximately $18.0 million of financing costs related to the global revolving credit facility. As of December 31, 2015, approximately $967.9 million was drawn under this facility and $8.7 million of letters of credit were issued, leaving approximately $0.9 billion available for use.

On January 15, 2016, the Operating Partnership refinanced our global revolving credit facility and entered into a global senior credit agreement for a $2.0 billion senior unsecured revolving credit facility, which we refer to as the 2016 global revolving credit facility, that replaced the $2.0 billion revolving credit facility executed on August 15, 2013, as amended. The 2016 global revolving credit facility provides for borrowings in Australian dollars, British pounds sterling, Canadian dollars, Euros, Hong Kong dollars, Japanese yen, Singapore dollars, and U.S. dollars, and includes the ability to add additional currencies in the future. The 2016 global revolving credit facility has an accordion feature that would enable us to increase the borrowing capacity of the credit facility to $2.5 billion, subject to the receipt of lender commitments and other conditions precedent. The 2016 global revolving credit facility matures on January 15, 2020, with two six-month extension options available.

The 2016 global revolving credit facility contains various restrictive covenants, including limitations on our ability to incur additional indebtedness, make certain investments or merge with another company, and requirements to maintain financial coverage ratios, including with respect to unencumbered assets. In addition, the 2016 global revolving credit facility restricts Digital Realty Trust, Inc. from making distributions to its stockholders, or redeeming or otherwise repurchasing shares of its capital stock, after the occurrence and during the continuance of an event of default, except in limited circumstances including as necessary to enable Digital Realty Trust, Inc. to maintain its qualification as a REIT and to minimize the payment of income or excise tax. As of December 31, 2015, we were in compliance with all of such covenants.

Unsecured Term Loan

On August 15, 2013, we refinanced our then-existing senior unsecured multi-currency term loan facility, increasing its total borrowing capacity to $1.0 billion from $750.0 million. Pursuant to the accordion feature, total commitments could be increased to $1.1 billion, subject to the receipt of lender commitments and other conditions precedent. The facility matured on April 16, 2017, with two six-month extension options available. Interest rates were based on our senior unsecured debt ratings and were 120 basis points over the applicable index for floating rate advances. Funds were available in U.S, Singapore and Australian dollars, as well as Euro and British pound sterling denominations with the option to add Hong Kong dollars and Japanese yen upon an accordion exercise. Based on exchange rates in effect at December 31, 2015, the balance outstanding was approximately $1.0 billion. We have used borrowings under the term loan for acquisitions, repayment of indebtedness, development, working capital and general corporate purposes. The covenants under this loan are consistent with our global revolving credit facility and, as of December 31, 2015, we were in compliance with all of such covenants. As of December 31, 2015, we have capitalized approximately $8.4 million of financing costs related to the unsecured term loan.

On January 15, 2016, the Operating Partnership refinanced the senior unsecured multi-currency term loan facility and entered into a term loan agreement which governs (i) a $1.25 billion 5-year senior unsecured term loan (the “5-Year Term Loan”) and (ii) a $300 million 7-year senior unsecured term loan (the “7-Year Term Loan”). The term loan agreement replaced the $1.0 billion term loan agreement executed on April 16, 2012, as amended. The term loan agreement provides for borrowings in Australian dollars, British pounds sterling, Canadian dollars, Euros, Hong Kong dollars, Japanese yen, Singapore dollars and U.S. dollars. The maturity date of the 5-Year Term Loan is January 15, 2021 and the maturity date of the 7-Year Term Loan is January 15, 2023. In addition, we have the ability from time to time to increase the aggregate size of lending under the Term Loan Agreement from $1.5 billion up to $1.8 billion, subject to receipt of lender commitments and other conditions precedent.

Unsecured Senior Notes

Prudential Shelf Facility

On January 20, 2010, the Operating Partnership closed the sale of $100.0 million aggregate principal amount of its senior unsecured term notes to Prudential Investment Management, Inc. and certain of its affiliates, or, collectively, Prudential, pursuant to a Note Purchase and Private Shelf Agreement, which we refer to as the Prudential shelf facility. The notes were issued in two series referred to as the series D and series E notes. The series D notes had a principal amount of $50.0 million, an interest-only rate of 4.57% per annum and a five-year maturity, and the series E notes have a principal amount of $50.0 million, an interest-only rate of 5.73% per annum and a seven-year maturity. On February 3, 2010, the Operating Partnership closed the sale of an additional $17.0 million aggregate principal amount of its senior unsecured term notes, which we refer to as the series F notes, to Prudential pursuant to the Prudential shelf facility. The series F notes had an interest-only rate of 4.50% per annum and a five-year maturity. We used the proceeds of the series D, series E and series F notes to fund acquisitions, to temporarily repay borrowings under our corporate revolving credit facility, to fund working capital and for general corporate purposes. The sale of the series A ($25.0 million), series B ($33.0 million) and series C ($25.0 million) notes were completed in July 2008, November 2008 and January 2009, respectively. We could prepay the notes of any series, in whole or in part, at any time at a price equal to the principal amount and accrued interest of the notes being prepaid, plus a make-whole provision. On December 8, 2010, the Operating Partnership and Prudential entered into an amendment to the Note Purchase and Private Shelf Agreement, increasing the capacity of the Prudential shelf facility from $200.0 million to $250.0 million. Our ability to make additional issuances of notes under the Prudential shelf facility expired on July 24, 2011, with $50.0 million remaining unissued under the shelf facility. On July 25, 2011, we repaid the $25.0 million of 7.00% Series A unsecured notes under the Prudential shelf facility at maturity. On November 5, 2013, we repaid the $33.0 million of 9.32% Series B unsecured notes under the Prudential shelf facility at maturity. On January 20, 2015 and February 3, 2015, we repaid the $50.0 million of 4.57% Series D unsecured notes and $17.0 million of 4.50% Series F unsecured notes under the Prudential shelf facility at maturity, respectively. As of December 31, 2015 and 2014, there was $75.0 million and $142.0 million of unsecured senior notes outstanding, respectively.

On August 15, 2013, concurrent with the refinancing of the global revolving credit facility, the Operating Partnership and Digital Realty Trust, Inc. and the other subsidiary guarantors set forth therein entered into Amendment No.1to the Amended and Restated Note Purchase and Private Shelf Agreement with Prudential to conform the restrictive and financial covenants of the original Prudential shelf facility that apply to the outstanding Series B, C, D, E and F Notes under the Prudential shelf facility to those in the global revolving credit facility described above and, subject to the completion of specified conditions, to authorize the potential issuance and sale of up to $50.0 million of additional senior unsecured fixed-rate term notes. The Prudential shelf facility contains restrictive covenants that are identical to those in our global revolving credit facility.

Senior Notes

5.875% Notes due 2020

On January 28, 2010, the Operating Partnership issued $500.0 million aggregate principal amount of notes, maturing on February 1, 2020 with an interest rate of 5.875% per annum (the 2020 Notes). The purchase price paid by the initial purchasers was 98.296% of the principal amount. The 2020 Notes are general unsecured senior obligations of the Operating Partnership, rank equally in right of payment with all other senior unsecured indebtedness of the Operating Partnership and are fully and unconditionally guaranteed by Digital Realty Trust, Inc. Interest on the 2020 Notes is payable on February 1 and August 1 of each year, beginning on August 1, 2010. The net proceeds from the offering after deducting the original issue discount of approximately $8.5 million and underwriting commissions and expenses of approximately $4.4 million was approximately $487.1 million. The 2020 Notes have been reflected net of discount in the consolidated balance sheet.

The indenture governing the 2020 Notes contains certain covenants, including (1) a leverage ratio not to exceed 60%, (2) a secured debt leverage ratio not to exceed 40% and (3) an interest coverage ratio of greater than 1.50, and also requires us to maintain total unencumbered assets of not less than 150% of the aggregate principal amount of unsecured debt. At December 31, 2015, we were in compliance with each of these financial covenants.

We entered into a registration rights agreement whereby the Operating Partnership agreed to conduct an offer to exchange the 2020 Notes for a new series of publicly registered notes with substantially identical terms. If the Operating Partnership did not fulfill certain of its obligations under the registration rights agreement, it would have been required to pay liquidated damages to the holders of the 2020 Notes. No separate contingent obligation was recorded as no liquidated damages became probable. We filed a registration statement with the U.S. Securities and Exchange Commission in June 2010 in connection with the exchange offer, which was declared effective in September 2010. We completed the exchange offer on November 5, 2010.

5.250% Notes due 2021

On March 8, 2011, the Operating Partnership issued $400.0 million aggregate principal amount of notes, maturing on March 15, 2021 with an interest rate of 5.250% per annum (the 2021 Notes). The purchase price paid by the initial purchasers was 99.775% of the principal amount. The 2021 Notes are general unsecured senior obligations of the Operating Partnership, rank equally in right of payment with all other senior unsecured indebtedness of the Operating Partnership and are fully and unconditionally guaranteed by Digital Realty Trust, Inc. Interest on the 2021 Notes is payable on March 15 and September 15 of each year, beginning on September 15, 2011. The net proceeds from the offering after deducting the original issue discount of approximately $0.9 million and underwriting commissions and expenses of approximately $3.6 million was approximately $395.5 million. The 2021 Notes have been reflected net of discount in the consolidated balance sheet.

The indenture governing the 2021 Notes contains certain covenants, including (1) a leverage ratio not to exceed 60%, (2) a secured debt leverage ratio not to exceed 40% and (3) an interest coverage ratio of greater than 1.50, and also requires us to maintain total unencumbered assets of not less than 150% of the aggregate principal amount of unsecured debt. At December 31, 2015, we were in compliance with each of these financial covenants.

3.625% Notes due 2022

On September 24, 2012, the Operating Partnership issued $300.0 million in aggregate principal amount of notes, maturing on October 1, 2022 with an interest rate of 3.625% per annum (the 2022 Notes). The purchase price paid by the initial purchasers was 98.684% of the principal amount. The 2022 Notes are general unsecured senior obligations of the Operating Partnership, rank equally in right of payment with all other senior unsecured indebtedness of the Operating Partnership and are fully and unconditionally guaranteed by Digital Realty Trust, Inc. Interest on the 2022 Notes is payable on April 1 and October 1 of each year, beginning on April 1, 2013. The net proceeds from the offering after deducting the original issue discount of approximately $3.9 million and underwriting commissions and expenses of approximately $3.0 million was approximately $293.1 million. We used the net proceeds from this offering to temporarily repay borrowings under our global revolving credit facility. The 2022 Notes have been reflected net of discount in the consolidated balance sheet.

The indenture governing the 2022 Notes contains certain covenants, including (1) a leverage ratio not to exceed 60%, (2) a secured debt leverage ratio not to exceed 40% and (3) an interest coverage ratio of greater than 1.50, and also requires us to maintain total unencumbered assets of not less than 150% of the aggregate principal amount of unsecured debt. At December 31, 2015, we were in compliance with each of these financial covenants.

4.750% Notes due 2023

On April 1, 2014, Digital Stout Holding, LLC, a wholly-owned subsidiary of Digital Realty Trust, L.P., issued £300.0 million (or approximately $498.9 million based on the April 1, 2014 exchange rate of £1.00 to $1.66) aggregate principal amount of its 4.750% Guaranteed Notes due 2023, or the 2023 Notes. The 2023 Notes are senior unsecured obligations of Digital Stout Holding, LLC and are fully and unconditionally guaranteed by Digital Realty Trust, Inc. and Digital Realty Trust, L.P. Interest on the 2023 Notes is payable semiannually in arrears at a rate of 4.750% per annum. The 2023 Notes mature on October 13, 2023. The net proceeds from the offering after deducting the original issue discount of approximately $3.0 million and underwriting commissions and estimated expenses of approximately $5.0 million was approximately $490.9 million. We used the net proceeds from this offering to temporarily repay borrowings under our global revolving credit facility. The 2023 Notes have been reflected net of discount in the condensed consolidated balance sheet. The indenture governing the 2023 Notes contains certain covenants, including (1) a leverage ratio not to exceed 60%, (2) a secured debt leverage ratio not to exceed 40% and (3) an interest coverage ratio of greater than 1.50, and also requires us to maintain total unencumbered assets of not less than 150% of the aggregate principal amount of the unsecured debt. At December 31, 2015, we were in compliance with these financial covenants.

4.250% Notes due 2025

On January 18, 2013, Digital Stout Holding, LLC, a wholly-owned subsidiary of the Operating Partnership, issued £400.0 million (or approximately $634.8 million based on the exchange rate of £1.00 to $1.59 on January 18, 2013) aggregate principal amount of its 4.250% Guaranteed Notes due 2025, or the 2025 Notes. The 2025 Notes are senior unsecured obligations of Digital Stout Holding, LLC and are fully and unconditionally guaranteed by the Company and the Operating Partnership. Interest on the 2025 Notes is payable semiannually in arrears at a rate of 4.250% per annum. The net proceeds from the offering after deducting the original issue discount of approximately $4.8 million and underwriting commissions and estimated expenses of approximately $5.8 million was approximately $624.2 million. We used the net proceeds from this offering to temporarily repay borrowings under our global revolving credit facility. The 2025 Notes have been reflected net of discount in the consolidated balance sheet. The indenture governing the 2025 Notes contains certain covenants, including (1) a leverage ratio not to exceed 60%, (2) a secured debt leverage ratio not to exceed 40% and (3) an interest coverage ratio of greater than 1.50, and also requires us to maintain total unencumbered assets of not less than 150% of the aggregate principal amount of the unsecured debt. At December 31, 2015, we were in compliance with all of such covenants.

3.950% Notes due 2022

On June 23, 2015, the Operating Partnership issued $500.0 million in aggregate principal amount of notes, maturing on July 1, 2022 with an interest rate of 3.950% per annum (the 3.950% 2022 Notes). The public offering price was 99.236% of the principal amount. The 3.950% 2022 Notes are general unsecured senior obligations of the Operating Partnership, rank equally in right of payment with all other senior unsecured indebtedness of the Operating Partnership and are fully and unconditionally guaranteed by Digital Realty Trust, Inc. Interest on the 3.950% 2022 Notes is payable on January 1 and July 1 of each year, beginning on January 1, 2016. The net proceeds from the offering after deducting the original issue discount of approximately $3.8 million and underwriting commissions and expenses of approximately $4.4 million was approximately $491.8 million. The Operating Partnership has used and will use the net proceeds from the offering of the 3.950% 2022 Notes to fund certain eligible green projects, including the development and redevelopment of such projects. Pending such uses, the Operating Partnership temporarily repaid borrowings under its global revolving credit facility. The 3.950% 2022 Notes have been reflected net of discount in the condensed consolidated balance sheet. The indenture governing the 3.950% 2022 Notes contains certain covenants, including (1) a leverage ratio not to exceed 60%, (2) a secured debt leverage ratio not to exceed 40% and (3) an interest coverage ratio of greater than 1.50, and also requires us to maintain total unencumbered assets of not less than 150% of the aggregate principal amount of unsecured debt. At December 31, 2015, we were in compliance with each of these financial covenants.

3.400% Notes due 2020 and 4.750% Notes due 2025

On October 1, 2015, Digital Delta Holdings, LLC, a Delaware limited liability company and wholly owned subsidiary of Digital Realty Trust, Inc., issued $500.0 million aggregate principal amount of its 3.400% Notes due 2020 (the “3.400% 2020 notes”) and $450.0 million aggregate principal amount of its 4.750% Notes due 2025 (the “4.750% 2025 notes” and together with the 3.400% 2020 notes, the “Delta Holdings Notes”), fully and unconditionally guaranteed by Digital Realty Trust, Inc. and Digital Realty Trust, L.P. The terms of the Delta Holdings Notes are governed by an indenture, dated as of October 1, 2015, by and among Digital Delta Holdings, LLC, as issuer, Digital Realty Trust, Inc. and Digital Realty Trust, L.P., as guarantors, and Wells Fargo Bank, National Association, as trustee. The indenture contains various restrictive covenants, including limitations on the ability of Digital Realty Trust, L.P. and its subsidiaries to incur additional indebtedness and requirements to maintain a pool of unencumbered assets.

Digital Delta Holdings, LLC used the net proceeds from the offering to fund a portion of the aggregate purchase price for the Telx Acquisition.

The purchase price paid by the initial purchasers for the 3.400% 2020 notes and 4.750% 2025 notes was 99.777% and 100.000% of the principal amount thereof, respectively. The 3.400% 2020 notes and 4.750% 2025 notes bear interest at 3.400% and 4.750% per annum, respectively. Interest is payable on April 1 and October 1 of each year, beginning April 1, 2016, until the respective maturity dates of October 1, 2020 and October 1, 2025.

Pursuant to the terms of the indenture, within five business days following the consummation of the Telx Acquisition, Digital Delta Holdings, LLC was required to merge with and into Digital Realty Trust, L.P., with Digital Realty Trust, L.P. surviving the merger (the “Operating Partnership Merger”) and to assume Digital Delta Holdings, LLC’s obligations under the Delta Holdings Notes and the related indenture and registration rights agreement by operation of law. The Operating Partnership Merger was consummated on October 13, 2015.

Subsequent to the Operating Partnership Merger, the Notes are the Operating Partnership’s senior unsecured obligations and rank equally in right of payment with all of the Operating Partnership’s other unsecured and unsubordinated indebtedness from time to time outstanding. However, the Delta Holdings Notes are effectively subordinated in right of payment to all of the operating partnership’s existing and future secured indebtedness (to the extent of the collateral securing the same) and to all existing and future liabilities and preferred equity of the Operating Partnership’s subsidiaries. Prior to the completion of the Operating Partnership Merger, Digital Realty Trust, Inc. and the Operating Partnership guaranteed the obligations of the Delta Holdings Notes. Following the completion of the Operating Partnership Merger, the Delta Holdings Notes became the senior unsecured obligations of the Operating Partnership and remained guaranteed by Digital Realty Trust, Inc.

The Delta Holdings Notes will be redeemable in whole at any time or in part from time to time, at the Operating Partnership’s option, at a redemption price equal to the sum of:



	•		an amount equal to 100% of the principal amount of the Delta Holdings Notes to be redeemed plus accrued and unpaid interest up to, but not including, the redemption date; and



	•		a make-whole premium calculated in accordance with the indenture.

Notwithstanding the foregoing, if any of the 3.400% 2020 Notes are redeemed on or after September 1, 2020 or if any of the 4.750% 2025 Notes are redeemed on or after July 1, 2025, the redemption price will not include a make-whole premium.

The table below summarizes our debt maturities and principal payments as of December 31, 2015 (in thousands):



	Global Revolving Credit Facility(1)		Unsecured Term Loan (1)		Prudential Shelf Facility		Senior Notes (2)			Mortgage Loans (3)		Total Debt
2016	$	—	$	—	$	25,000	$	—		$	191,979	$	216,979
2017	967,884		924,568		50,000		—			108,395		2,050,847
2018	—		—		—		—			593		593
2019	—		—		—		—			644		644
2020	—		—		—		1,000,000			1,133		1,001,133
Thereafter	—		—		—		2,681,520			—		2,681,520
Subtotal	$	967,884	$	924,568	$	75,000	$	3,681,520		$	302,744	$	5,951,716
Unamortized discount	—		—		—		(17,914		)	—		(17,914		)
Unamortized premium	—		—		—		—			439		439
Total	$	967,884	$	924,568	$	75,000	$	3,663,606		$	303,183	$	5,934,241


(1)	Subject to two six -month extension options exercisable by us. The bank group is obligated to grant the extension options provided we give proper notice, we make certain representations and warranties and no default exists under the global revolving credit facility and the unsecured term loan, as applicable.


(2)	On January 6, 2016, we repaid the $25.0 million of 9.68% Series C unsecured notes under the Prudential shelf facility at maturity.


(3)	In January and February 2016, we repaid in full two mortgage loans in the aggregate amount of $51.5 million.