How Illinois, Washington, Massachusetts and Georgia set sales tax deadlines

What to take away

Four states, four calendars: how each state sets your filing frequency

In most states you do not pick how often you file sales tax. The revenue department looks at the tax you collected in a lookback period and assigns a frequency: monthly, quarterly or annual. Illinois, Washington, Massachusetts and Georgia all work this way, though the thresholds and the review dates differ.

That assignment matters for a small business selling into more than one state. A shop in Chicago might file monthly in Illinois, quarterly in Washington and annually in Georgia, all in the same year. Miss the change letter and you file on the old schedule.

Frequency is not permanent. When sales rise or fall, a state can move you to a different schedule at its next review.

The practical answer is to keep a frequency column in your sales tax tracker, separate from the due-date column. Then a month-end routine can sort tasks by schedule instead of by state.

A chart of accounts that separates sales tax payable by state makes the return figures easy to pull at period end.

Illinois sales tax returns and the state's filing schedule

Illinois sales tax is administered by the Illinois Department of Revenue. Retailers file Form ST-1, the sales and use tax return, and the return covers both state and local taxes collected in the period.

Illinois sets the schedule from prior tax liability. The department applies liability ranges to decide between annual, quarterly and monthly filing, and it lists those ranges in its sales tax guidance.

Smaller sellers file annually, moderate sellers quarterly, and higher-volume sellers monthly. A review can move you between ranges, and the notice states the new frequency and the first period it applies to.

Illinois sales tax filing generally follows a 20th-of-the-month deadline. Monthly filers report the prior month by the 20th. Quarterly filers report by the 20th of the month after the quarter ends. Annual filers report by January 20 of the following year.

A late return or payment can bring penalties and interest, so the 20th is the date to circle. If the 20th falls on a weekend or state holiday, the deadline moves to the next business day.

Illinois also runs a separate prepayment requirement for some large taxpayers. If the department has assigned you prepayments, those amounts are due earlier in the month, not on the 20th. Read the notice rather than assuming.

For a multi-state seller, Illinois is the state that most often lands on a monthly schedule first. High sales through Chicago and its home-rule local taxes push liability up quickly, and the department responds by moving the account to monthly filing.

Close the month with a bank reconciliation so the sales tax payable balance you report matches the return you filed.

Washington retail sales tax and the Department of Revenue's due dates

Washington retail sales tax is a destination-based tax administered by the Washington State Department of Revenue. Rates vary by location, so the same sale can carry a different rate depending on the buyer's address. The department publishes current rates and reporting rules for retail sales tax.

The return is the combined excise tax return, filed through the Department of Revenue's My DOR system.

Washington assigns a reporting frequency based on the tax due in a calendar year, and the department lists the liability ranges for annual, quarterly and monthly reporting in its filing guidance.

Sellers with small liability file annually, mid-size sellers file quarterly, and larger sellers file monthly. The department reviews the account when the annual total crosses a range, and it sends notice of the new frequency.

Reporting periods in Washington are calendar months, quarters or years, depending on the assigned frequency. The return covers tax collected in that period, plus any use tax owed on purchases where no sales tax was charged.

The Department of Revenue publishes the full schedule for filing frequencies and due dates, including state taxes beyond sales tax. If the last day falls on a weekend or holiday, the deadline shifts to the next business day.

Returns are due the last day of the month after the reporting period. Annual filers, who report the calendar year, file by January 31.

Washington is also strict about a use tax line on the return. Small businesses that buy goods without paying sales tax, from out-of-state suppliers or online sellers, owe use tax on those purchases. The return is where you report it.

Because Washington rates are destination-based, a bookkeeping routine that records the buyer's city and ZIP on every invoice saves hours at filing time. Without that detail, the return becomes a guessing game.

Massachusetts sales and use tax filing guidance

Massachusetts sales and use tax is administered by the Massachusetts Department of Revenue. Sellers register, collect the state rate plus any local option, and file a sales and use tax return for each period.

The return is Form ST-9, filed through MassTaxConnect. Returns are due on the 20th of the month after the reporting period, and annual filers file by January 20.

The Department of Revenue assigns a filing frequency from your annual liability, and its guidance lists the ranges behind the annual, quarterly and monthly schedules. Smaller sellers file annually, moderate sellers quarterly, and larger sellers monthly. A review can move a business to a more frequent schedule, and the department notifies you of the change.

Massachusetts also requires many sellers to file electronically. The state's online portal handles registration, returns and payments in one place, and the Department of Revenue publishes guidance for Massachusetts sales and use tax filing and deadlines.

A detail that catches multi-state sellers: Massachusetts treats some services and digital goods as taxable that other states leave alone. If you sell software or a service into the state, check the taxability rules before you assume the sale is exempt.

Use tax works the same way as in Washington. If you buy equipment or supplies without paying Massachusetts sales tax, you owe use tax on the purchase and report it on the return.

Keep a separate liability account for Massachusetts tax if you collect in other states. Otherwise the quarterly accounts payable run is harder to reconcile when you pay the state.

Georgia sales tax return due dates and frequency

Georgia sales and use tax is administered by the Georgia Department of Revenue. Sellers file Form ST-3, the sales and use tax return, which covers state tax plus any local sales tax collected in the period.

Georgia assigns filing frequency from prior tax liability, using ranges the department publishes in its sales and use tax guidance. Smaller sellers file annually or quarterly, and larger sellers file monthly. A review can adjust the frequency as reported liability grows, and the department sends notice of the new schedule.

Georgia sales tax due dates land on the 20th of the month after the reporting period. Monthly filers report the prior month by the 20th. Quarterly filers report by the 20th of the month after the quarter. Annual filers report by January 20 of the following year.

The Department of Revenue publishes the sales and use tax rules, including registration and return details, for Georgia sales and use tax. The department also keeps a page of tax FAQs, due dates and other resources that answers common filing questions.

Georgia has a prepayment rule for some large taxpayers, similar to Illinois. If the department assigns prepayments, part of the month's tax is due before the 20th. Read the notice and calendar the earlier date.

Local sales tax in Georgia adds complexity. County and city taxes sit on top of the state rate, and the combined rate depends on where the sale is delivered. Keep the delivery address on file for every taxable sale.

For a small seller, Georgia is often the state where annual filing is available longest. That makes it tempting to ignore until January, which is exactly when the return and the prior year's books both come due.

Turning each schedule into a month-end checklist

A frequency is only useful if it turns into tasks. The month-end checklist below covers the four schedules. Run the items that match your assigned frequency in each state.

For annual filers, most of these items move to January. Illinois and Georgia annual returns are due January 20, Washington's is due January 31, and Massachusetts annual filers file by January 20. Set a January reminder in December so the return does not compete with year-end close.

A small retailer in Chicago sells online into Washington, Massachusetts and Georgia. Illinois assigns monthly filing, so the ST-1 is due the 20th each month. Washington assigns quarterly reporting, so returns are due April 30, July 31, October 31 and January 31.

Massachusetts assigns quarterly filing, due the 20th of the month after each quarter. Georgia assigns annual filing, due January 20.

That single business has four different rhythms. The month-end checklist handles the monthly Illinois return, the quarterly states land on three months of the year, and January carries all four. Writing the dates into a shared calendar at the start of the year is the cheapest control available.

If you record sales tax as revenue instead of a liability, the return figures and the books will never agree. A short review of bookkeeping foundations prevents that error before it spreads.

At year end, the sales tax payable accounts should clear to near zero once all returns are filed. If a balance lingers, either a return was missed or a payment was posted to the wrong period. The profit and loss statement will not show the problem, because sales tax collected is not revenue. Only the balance sheet will.

A combined due-date table for a multi-state bookkeeper

The table below summarizes the four schedules. Treat it as a starting point, then confirm your own assigned frequency.

Two patterns stand out. Illinois, Massachusetts and Georgia share the 20th as the core deadline, which makes a single monthly reminder useful. Washington uses the last day of the following month, so its deadline drifts with the length of the month.

Prepayment rules break the pattern in Illinois and Georgia for large taxpayers. If you receive a prepayment notice, add the earlier date to the calendar and keep it separate from the return deadline.

Weekend and holiday shifts apply in all four states. When a due date falls on a Saturday, Sunday or legal holiday, the deadline moves to the next business day. Do not use that as a planning assumption; file early instead.

Finally, keep the registration records for each state with the filing calendar. When you add a state, the first question to answer is the assigned frequency, and the second is whether the state requires electronic filing. Both answers change the month-end routine.

Common questions