Income Taxes	9 Months Ended
Jun. 27, 2020
Income Tax Disclosure [Abstract]
Income Taxes	12. Income Taxes In the third quarter and first nine months of 2020, our effective tax rate was 22% on pre-tax income of $44.5 million and 3% on a pre-tax income of $79.3 million, respectively, compared to (2,940%) on a pre-tax loss of $(0.5) million and (177%) on a pre-tax loss of $(13.5) million in the third quarter and first nine months of 2019, respectively. In the first nine months of 2020 and 2019, our effective tax rate differed from the statutory federal income tax rate of 21% due to U.S. tax reform, our corporate structure in which our foreign taxes are at a net effective tax rate lower than the U.S. rate, the excess tax benefit related to stock-based compensation and the indirect effects of the adoption of ASC 606. Additionally, in the first nine months of 2020 and 2019, we reduced the valuation allowance by $21.2 million and $1.8 million as the result of the Onshape and Frustum acquisitions, respectively. A significant amount of our foreign earnings is generated by our subsidiaries organized in Ireland. In 2020 and 2019, the foreign rate differential predominantly relates to these Irish earnings. On March 27, 2020, the U.S. Federal government enacted the Coronavirus Aid, Relief, and Economic Security Act (the “CARES ACT”). The CARES Act is an emergency economic stimulus package in response to the coronavirus outbreak, which among other things contains numerous income tax provisions. While we continue to evaluate the impact of the CARES Act, we do not currently believe it will have a material impact on our consolidated financial statements or related disclosures. We have concluded, based on the weight of available evidence, that a full valuation allowance continues to be required against our U.S. net deferred tax assets as they are not more likely than not to be realized in the future. We will continue to reassess our valuation allowance requirements each financial reporting period. In the normal course of business, PTC and its subsidiaries are examined by various taxing authorities, including the Internal Revenue Service in the U.S. We regularly assess the likelihood of additional assessments by tax authorities and provide for these matters as appropriate. We are currently under audit by tax authorities in several jurisdictions. Audits by tax authorities typically involve examination of the deductibility of certain permanent items, limitations on net operating losses and tax credits. As of June 27, 2020 and September 30, 2019, we had unrecognized tax benefits of $14.7 million and $11.5 million, respectively. If all our unrecognized tax benefits as of June 27, 2020 were to become recognizable in the future, we would record a benefit to the income tax provision of $14.7 million, which would be partially offset by an increase in the U.S. valuation allowance of $7.2 million. Although we believe our tax estimates are appropriate, the final determination of tax audits and any related litigation could result in favorable or unfavorable changes in our estimates. We believe it is reasonably possible that within the next 12 months the amount of unrecognized tax benefits related to the resolution of multi-jurisdictional tax positions could be reduced by up to $0.7 million. In the fourth quarter of 2016, we received an assessment of approximately $12 million from the tax authorities in South Korea. The assessment relates to various tax issues, primarily foreign withholding taxes. We have appealed and intend to vigorously defend our positions. We believe that upon completion of a multi-level appeal process it is more likely than not that our positions will be sustained. Accordingly, we have not recorded a tax reserve for this matter. We paid this assessment in the first quarter of 2017 and have recorded the amount in other assets, pending resolution of the appeal process. If the South Korean tax authorities were to prevail then, in addition to the $12 million already assessed, the potential additional exposure through the third quarter of 2020 would be approximately $16 million. We are continuing to work with our advisors during the court process and still believe our position is sustainable. In April 2020 we became aware of a potential new interpretation of a withholding tax law in a non-U.S. jurisdiction and its application to certain transactions that was not previously reasonably knowable by us. We have evaluated our information and made an estimate of the potential tax liability, which was recorded in the third quarter of 2020 and had an immaterial impact to our consolidated financial statements. In July 2015, the U.S. Tax Court issued an opinion in Altera Corp. v. Commissioner related to the treatment of stock-based compensation expense in an intercompany cost-sharing arrangement. The opinion invalidated part of a treasury regulation requiring stock-based compensation to be included in any qualified intercompany cost-sharing arrangement. The Company follows the 2015 Tax Court opinion, which was subsequently overturned by the Ninth Circuit Court of Appeals. All appeals have now been exhausted and the Altera decision is considered to be final in the Ninth Circuit. Because the Company does not reside in the Ninth Circuit and is therefore not bound by this decision, we have determined no adjustment is required to the consolidated financial statements as a result of this ruling.

Income Taxes

9 Months Ended

Jun. 27, 2020

12. Income Taxes

In the third quarter and first nine months of 2020, our effective tax rate was 22% on pre-tax income of $44.5 million and 3% on a pre-tax income of $79.3 million, respectively, compared to (2,940%) on a pre-tax loss of $(0.5) million and (177%) on a pre-tax loss of $(13.5) million in the third quarter and first nine months of 2019, respectively. In the first nine months of 2020 and 2019, our effective tax rate differed from the statutory federal income tax rate of 21% due to U.S. tax reform, our corporate structure in which our foreign taxes are at a net effective tax rate lower than the U.S. rate, the excess tax benefit related to stock-based compensation and the indirect effects of the adoption of ASC 606. Additionally, in the first nine months of 2020 and 2019, we reduced the valuation allowance by $21.2 million and $1.8 million as the result of the Onshape and Frustum acquisitions, respectively. A significant amount of our foreign earnings is generated by our subsidiaries organized in Ireland. In 2020 and 2019, the foreign rate differential predominantly relates to these Irish earnings.

On March 27, 2020, the U.S. Federal government enacted the Coronavirus Aid, Relief, and Economic Security Act (the “CARES ACT”). The CARES Act is an emergency economic stimulus package in response to the coronavirus outbreak, which among other things contains numerous income tax provisions. While we continue to evaluate the impact of the CARES Act, we do not currently believe it will have a material impact on our consolidated financial statements or related disclosures.

We have concluded, based on the weight of available evidence, that a full valuation allowance continues to be required against our U.S. net deferred tax assets as they are not more likely than not to be realized in the future. We will continue to reassess our valuation allowance requirements each financial reporting period.

In the normal course of business, PTC and its subsidiaries are examined by various taxing authorities, including the Internal Revenue Service in the U.S. We regularly assess the likelihood of additional assessments by tax authorities and provide for these matters as appropriate. We are currently under audit by tax authorities in several jurisdictions. Audits by tax authorities typically involve examination of the deductibility of certain permanent items, limitations on net operating losses and tax credits.

As of June 27, 2020 and September 30, 2019, we had unrecognized tax benefits of $14.7 million and $11.5 million, respectively. If all our unrecognized tax benefits as of June 27, 2020 were to become recognizable in the future, we would record a benefit to the income tax provision of $14.7 million, which would be partially offset by an increase in the U.S. valuation allowance of $7.2 million.

Although we believe our tax estimates are appropriate, the final determination of tax audits and any related litigation could result in favorable or unfavorable changes in our estimates. We believe it is reasonably possible that within the next 12 months the amount of unrecognized tax benefits related to the resolution of multi-jurisdictional tax positions could be reduced by up to $0.7 million.

In the fourth quarter of 2016, we received an assessment of approximately $12 million from the tax authorities in South Korea. The assessment relates to various tax issues, primarily foreign withholding taxes. We have appealed and intend to vigorously defend our positions. We believe that upon completion of a multi-level appeal process it is more likely than not that our positions will be sustained. Accordingly, we have not recorded a tax reserve for this matter. We paid this assessment in the first quarter of 2017 and have recorded the amount in other assets, pending resolution of the appeal process. If the South Korean tax authorities were to prevail then, in addition to the $12 million already assessed, the potential additional exposure through the third quarter of 2020 would be approximately $16 million. We are continuing to work with our advisors during the court process and still believe our position is sustainable.

In April 2020 we became aware of a potential new interpretation of a withholding tax law in a non-U.S. jurisdiction and its application to certain transactions that was not previously reasonably knowable by us. We have evaluated our information and made an estimate of the potential tax liability, which was recorded in the third quarter of 2020 and had an immaterial impact to our consolidated financial statements.

In July 2015, the U.S. Tax Court issued an opinion in Altera Corp. v. Commissioner related to the treatment of stock-based compensation expense in an intercompany cost-sharing arrangement. The opinion invalidated part of a treasury regulation requiring stock-based compensation to be included in any qualified intercompany cost-sharing arrangement. The Company follows the 2015 Tax Court opinion, which was subsequently overturned by the Ninth Circuit Court of Appeals. All appeals have now been exhausted and the Altera decision is considered to be final in the Ninth Circuit. Because the Company does not reside in the Ninth Circuit and is therefore not bound by this decision, we have determined no adjustment is required to the consolidated financial statements as a result of this ruling.