Capital Gains Excise Tax returns due date moved to May 1, 2026

Important!

Disaster Relief: Revenue will work with businesses that cannot file or pay their taxes on time due to recent wildfire damage or other natural disasters. Learn more about disaster relief.

Ayuda por desastres: El Departamento de Ingresos trabajará con las empresas que no puedan presentar o pagar sus impuestos a tiempo debido a los daños causados por incendios forestales u otros desastres naturales. Conozca más sobre la ayuda en caso de desastre.

OLYMPIA, Wash. – March 25, 2026 – Tax Year 2025 Capital Gains tax returns and payments are due May 1, 2026.

The Internal Revenue Service (IRS) has extended tax filing and payment deadlines to May 1, 2026 for Washington state residents and businesses affected by severe storms and flooding that began Dec. 9, 2025. For convenience, the April 15, 2026 due date for all Washington Capital Gains tax returns and payments has been extended to May 1, 2026 for the 2025 filing year only.

Filing extensions

Individuals must request an extension for their state capital gains return by May 1, 2026, and receive a filing extension for their federal income tax return to be entitled to a filing extension. The extended filing deadline is Oct. 15, 2026.

A filing extension does not extend the due date for paying the capital gains tax due. Payments are due May 1, 2026.

The Department of Revenue is Washington state’s primary tax agency, nationally recognized as a trusted leader in tax administration and customer service. Revenue administers nearly 60 categories of taxes that help fund vital public services. It also oversees programs that return money to the public, including the Working Families Tax Credit and Unclaimed Property.