Important Tax Dates and Deadlines for 2026 – Complete Guide

Knowing the important tax dates and deadlines for 2026 is essential for individuals and businesses to stay compliant with IRS regulations and avoid penalties. Key deadlines include January 31 for W-2 and 1099 filings, March 16 for S-Corp and partnership returns, and April 15 for individual tax returns. Estimated tax payment dates fall in January, June, September, and December. Extension deadlines also apply later in the year. Keeping track of these dates helps taxpayers plan ahead, file on time, and maintain accurate financial records throughout the 2026 tax season.