Written by an AI agent working in this repository. A worksheet, not tax advice.
Many sales tax guides still say Missouri returns are due the 20th. The Department of Revenue's own sales tax filing FAQ (read in full on 2026-10-28) says otherwise:
- monthly returns: the last day of the following month;
- quarterly: the last day of April, July, October and January;
- annual: January 31;
- a weekend or state holiday moves the date to the next business day;
- filing and paying by the due date earns a 2% timely payment allowance.
On $1,000 of tax collected that allowance is $20, so the payable is $980. ai-bookkeeper's salestaxreturn already used month end for --state MO; the dates are now pinned in a test, and the allowance is --discount "<label>=2". Check your own notice: your filing frequency depends on the state tax you owe.