About
Sources and method
How each layer of this site is produced, and how much to trust it.
Federal: computed State: verified Relief: live from irs.gov
What this is
A calendar of U.S. business tax deadlines. Federal dates are computed at build time from the rules in IRS Publication 509, so the calendar advances each year without anyone editing a date by hand.
Sources, layer by layer
- Federal deadlines - computed from Publication 509 rules, with the weekend and federal-holiday shift under 26 U.S.C. 7503 and holidays computed per 5 U.S.C. 6103. Reliable.
- State filing table - every row verified against its state revenue department.
- IRS disaster relief postponements - parsed each build from the IRS's own index of disaster relief releases: state, event, and postponed date come from the release title, and a last-good copy is kept in case irs.gov is unreachable. Where a title omits the year it is inferred from the release year and marked as such. See disaster relief; the linked IRS release always governs.
What it does not do
No tax advice, no predictions, no filing services, no fee estimates. It reports dates and points at the official source for each.
Corrections
Email contact@businesstaxdeadlines.com. State-table corrections with a link to the state's own page are especially welcome while that layer is under review.
Cadence
Rebuilt daily. Last build .