Key takeaways
- The state assigns the filing frequency, usually when the account is set up, and the frequency sets the period and the due date.
- Texas, California and New York use different due dates, so one calendar rule per client does not work.
- The IRS weekend and holiday rule in Publication 509 governs federal due dates, not state sales tax.
- New York quarters are not calendar quarters, and a New York vendor must file even when it had no sales.
- Keep one calendar row per state account, and check each assigned schedule every year.
How states assign the filing frequency
Each state puts each sales tax account on a monthly, quarterly or yearly schedule. The assignment decides the reporting period and the due date, so it is the first fact to collect for each state. Texas tells the taxpayer by letter, after the permit application is approved, whether it will file monthly or quarterly. California assigns the frequency based on reported sales tax or on anticipated taxable sales at registration.
The dollar line is where states differ most. New York's Tax Bulletin ST-275 says combined taxable sales and purchases subject to use tax of $300,000 or more in a quarter require monthly filing. It also says a vendor who owes $3,000 or less in tax during an annual filing period files annually. The CDTFA and Texas pages checked for this guide do not state a dollar threshold for frequency, so for those states take the frequency from the notice on file.
Decision rule: if a New York client's taxable sales and purchases are approaching $300,000 in a quarter, ask for the quarter total when the quarter closes and check whether the account has moved to monthly before the next return. The bulletin text checked does not say which period a monthly assignment starts, so confirm that with the Tax Department before changing the calendar.
Due dates for monthly, quarterly and yearly filers
Texas quarterly reports are due April 20 for January through March, July 20 for April through June, October 20 for July through September, and January 20 for October through December. Monthly reports are due on the 20th of the month after the reporting month. Yearly filers report the previous year's sales by January 20, so the 2026 sales of a yearly filer are due January 20, 2027.
California's CDTFA lists quarterly returns due April 30 for January through March, July 31 for April through June, October 31 for July through September, and January 31 for October through December. Monthly returns are due on the last day of the month after the reporting period, so the June return is due July 31 and the July return is due August 31. Quarterly prepayment filers pay for the first two months of each quarter by the 24th of the following month, and the CDTFA points to CDTFA-367 for prepayment details. A yearly return for January through December is due January 31.
New York quarterly returns are due no later than 20 days after the quarter ends. New York's quarters are not calendar quarters: they run March 1 through May 31, June 1 through August 31, September 1 through November 30, and December 1 through February 28 or 29. The return for the quarter ending May 31 is due June 20, and annual returns are due by March 20 each year.
The weekend and holiday rule
IRS Publication 509 for 2026 says that if a due date falls on a Saturday, Sunday or legal holiday, the act is timely if performed no later than the next day that is not one of those. For federal purposes a legal holiday means a legal holiday in the District of Columbia. A statewide legal holiday delays a federal filing due date only when the IRS office where the return is filed is in that state, and it does not delay a federal tax deposit.
Sales tax follows each state's own rule. California extends the due date to the next business day when it falls on a weekend or state holiday. Texas moves a due date that falls on a Saturday, Sunday or legal holiday to the next working day. The New York bulletin checked for this guide sets the 20-day rule and does not restate a weekend rule, so confirm New York's current rule before setting an internal date.
Failure mode: a calendar built on the federal rule will apply the wrong holiday list to a state return. Fix it with one holiday list per state, taken from that state's revenue site each year, and set the internal target a few business days before the statutory date.
Build the calendar one account at a time
Use one row per state account, not one row per client. A client registered in three states has three schedules, and each row needs the frequency, the period definition, the due date rule, the holiday rule and the internal target date. Take the frequency from the state notice on file, because the notice is the state's own record of the assignment.
Generate the dates in this order. List the periods the account owes for the year, using that state's period definition. Apply the state's due date rule to each period, then its weekend and holiday rule. Set the internal target. Mark the zero-return periods, because a New York vendor must file for every assigned period even with no sales.
Worked example. A client has a Texas quarterly account, a California monthly account and a New York quarterly account, all reporting 2026 sales. The Texas return for July through September 2026 is due October 20, 2026. The California return for June 2026 is due July 31, 2026, and the one for July 2026 is due August 31, 2026. New York's quarter ending August 31, 2026 is due no later than September 20, 2026.
Failure modes and fixes
Stale frequency. A New York client that crossed the $300,000 line keeps a quarterly calendar after the account has moved to monthly filing, so the monthly returns are missed. Fix it by checking each account's assigned frequency every January, and after any quarter where taxable sales or purchases came close to the line.
Calendar quarters in New York. A calendar that uses March, June, September and December quarter ends misdates every New York return. Fix it with the ST-275 quarter definitions.
Missed prepayments. A California quarterly prepayment filer tracked only by the April 30 return misses the prepayments due on the 24th of the month. Put each prepayment date in the calendar as its own row.
Skipped zero returns. A dormant New York vendor that skips a return is still out of compliance, even with no tax due. Put every assigned period on the calendar, including the zero periods.
What to ask the client
Ask for the filing notice for each state account, not a list of registrations. Send: “Please upload the sales tax permit letter or account notice for each state where you are registered, and tell us whether each state put you on monthly, quarterly or yearly filing.” Ask for it before the first calendar is built.
For New York, add a second request, because the monthly line is based on the quarter total: “Tell us your taxable sales and purchases subject to use tax for each quarter this year, so we can check the $300,000 monthly filing line.” The answers decide whether the New York row is quarterly or monthly.
For the first calendar, ask for the last return filed in each state with its period and confirmation number. The period on that return shows where the next row starts, so the calendar does not begin on the wrong period.