LyondellBasell Industries N.V.

10. Income Taxes

For interim tax reporting, we estimate an annual effective tax rate which is applied to the year-to-date ordinary income. Tax effects of significant, unusual, or infrequently occurring items are excluded from the estimated annual effective tax rate calculation and recognized in the interim period in which they occur. Our effective income tax rate fluctuates based on, among other factors, changes in pre-tax income in countries with varying statutory tax rates, changes in valuation allowances, changes in foreign exchange gains or losses, the amount of nontaxable or nondeductible items, changes in unrecognized tax benefits associated with uncertain tax positions and changes in tax laws.

Our effective income tax rate for the first quarter of 2026 was (1.5)% compared to 61.0% for the first quarter of 2025. The lower effective tax rate for the first quarter of 2026 was due to foreign exchange losses coupled with a tax benefit associated with a tax refund claim that decreased the effective tax rate by 28.6 percentage points and 11.4 percentage points, respectively. In addition, changes in earnings in countries with varying statutory tax rates decreased the effective tax rate by 17.5 percentage points.