IRM · 10-Q · 2026Q3 · Full report

Income Tax Rate Changes

IRON MOUNTAIN INC · 2026-11-05 · Importance 51 · Surprise 64

The effective tax rate for the nine months ended September 30, 2026 was 20.4%, down from 44.7% in the prior-year period; for the third quarter it was 30.6%, compared with 16.1%. Nine-month income tax provision was $98.7 million, versus $47.7 million in 2025, despite the lower effective rate. The nine-month rate reflected the dividends-paid deduction and non-taxable income, partly offset by disallowed interest expense and foreign deferred-tax valuation allowances. Discrete tax items resulted in a $7.8 million provision for the nine months of 2026, compared with a $1.0 million provision in the same 2025 period.

Key facts

• Effective January 1, 2026, the One Big Beautiful Bill Act increased the maximum allowable share of a REIT’s assets held in taxable REIT subsidiaries from 20% to 25%. source
• Iron Mountain said it believed it qualified as a Pillar Two Excluded Entity as a Real Estate Investment Vehicle and that substantially all non-excluded non-U.S. jurisdictions qualified for one or more safe harbors. source
• Iron Mountain said remaining potentially applicable Pillar Two top-up taxes were not expected to have a material impact on its consolidated financial statements. source
• Iron Mountain's effective tax rate was 30.6% for the three months and 20.4% for the nine months ended September 30, 2026, compared with 16.1% and 44.7%, respectively, in 2025. source