When is the sales tax return due? Filing rhythms in NY, NJ and CT

A client with a shop on each side of the Hudson asks a single question — when is the sales tax return due? — and needs three answers. The quarters do not begin in the same month. The word “monthly” means a return in one state, a payment in another, and the only return there is in the third. And the figure that puts a business on the monthly grid measures sales in one state and tax in the other two, so the thresholds cannot be compared as written.

This page covers sales and use tax only. Connecticut individual estimated payments, the pass-through entity tax, CBT-100S and payroll returns are outside its scope. For whether a particular sale is taxable in the first place, see sales tax on personal care services: that page answers whether tax is owed, this one answers when the return is due.

What is due, and when

The fact each row stores is the offset — how long after a period closes the return is due. The dates beside it are derived from that offset rather than stored, so they cannot drift away from the rule they illustrate. Connecticut is the reason that matters: it moved its due date from the twentieth to the last day of the following month in 2015, which is one change to one field here and four separate edits in a table of written-down dates.

The dates above move

Every date in that table is where the rule falls on the calendar, before anything is done about weekends. All three states push a due date that lands on a weekend or a legal holiday to the next business day, and in 2026 that is not a footnote: it moves three of New York’s four quarterly dates. Treat the table as the rule and this section as what happens when the rule meets a particular year.

The Department: “If the due date of the return falls on a Saturday, Sunday, or legal holiday, it is due on the next business day.” General Construction Law §25-a is the statute underneath, extending any period that ends on a Saturday, Sunday or public holiday to the next succeeding business day, with a carve-out for periods fixed by contract. The two texts do not use the same word for a holiday, and neither enumerates which days qualify.tax.ny.gov, 2026 tax filing dates (page updated July 9, 2026) · N.Y. Gen. Constr. Law §25-a(1)

The Division of Taxation: “If the due date falls on a weekend or a legal holiday, the return and payment are due on the following business day.” New Jersey states the rule in its own guidance rather than in the Sales and Use Tax Act, and names no holidays; which days qualify is not settled here.nj.gov, Filing and Remitting Sales and Use Tax

Connecticut puts the rule in a statute of general application rather than on a sales tax page, so it reaches Form OS-114 without any sales-tax-specific authority. Conn. Gen. Stat. §12-39a(a): where the final day for performing an act in connection with any tax payable to the Commissioner of Revenue Services “falls on Saturday, Sunday or a legal holiday, as defined in section 1-4, the performance of such act will be considered timely if such act is performed on the next succeeding day which is not a Saturday, Sunday or legal holiday.” Which days are legal holidays is settled by §1-4, which is not stated here.Conn. Gen. Stat. §12-39a(a)

The rows are not aligned periods

New York’s sales tax quarters are not calendar quarters. §1136(b) requires quarterly returns “for quarterly periods ending on the last day of February, May, August and November of each year”, so the periods run March to May, June to August, September to November and December to February — each offset by a month from the calendar quarters New Jersey and Connecticut use. The consequence is about layout as much as dates: a table with the three states in columns and four filings in rows does not have one period of time in a row, and the due dates along a row are not alternatives for the same quarter.N.Y. Tax Law §1136 (Art. 28, Part 4) · TB-ST-275 (updated November 20, 2015; page updated June 4, 2026) · Sales & Use Tax Filing Chart (PDF, updated 2025) · Conn. Gen. Stat. §12-414(a), (b)(1), (e)(1)

What “monthly” means in each state

This is the part most often got backwards, and the firm’s own reference document had it backwards until this page was built. In New York and New Jersey a monthly obligation is added on top of a quarterly return that never lapses. In Connecticut the filing bases are mutually exclusive: a monthly filer files monthly and nothing else. Counting filings will not tell them apart — all three put a monthly-tier filer on twelve filings a year, by three different structures.

A New York vendor on the monthly grid does not stop filing quarterly. §1136(a)(2) requires the monthly return “in addition to filing a quarterly return described in paragraph one of this subdivision”, and §1136(a)(8) says a long-form part-quarterly filer “shall also be required to file a quarterly return for such quarter”. Tax Bulletin ST-265 shows it rather than asserting it: a filer closing mid-quarter files two ST-809s and an ST-810 covering the same days the ST-809s already covered, which a replacement regime cannot produce. What Form ST-810 replaces is Form ST-100 — the form that carries the quarter, not the quarterly obligation.N.Y. Tax Law §1136 (Art. 28, Part 4) · TB-ST-265 (updated June 13, 2014; page updated February 19, 2026) · TB-ST-275 (updated November 20, 2015; page updated June 4, 2026) · tax.ny.gov, Monthly filer forms (ST-809 series) (page updated July 20, 2026)

Form ST-809 is filed for the first two months of each quarter and not the third, which is reported on the ST-810 with the quarter. §1136(a)(9) defines the short form as available “for the first two months of any quarter”, and the Department publishes an ST-809 for March, April, June and July and for no May and no August — the third months of their quarters. §1136(a)(8) contemplates a long-form filer filing for every month of a quarter and then filing a quarterly return as well; the Department’s forms inventory does not implement that as four documents.tax.ny.gov, Monthly filer forms (ST-809 series) (page updated July 20, 2026) · N.Y. Tax Law §1136 (Art. 28, Part 4) · TB-ST-265 (updated June 13, 2014; page updated February 19, 2026)

A New Jersey seller on the monthly grid keeps filing quarterly. The Division: a registered seller “will be required to file quarterly returns and make quarterly payments. Some sellers must also make monthly payments.” The filing chart shows the same thing structurally — every quarter-end month carries Form ST-50 for “All Filers”, with no carve-out for sellers who paid by voucher in the two preceding months. What New Jersey adds is a remittance rather than a return: the Monthly Voucher “is used to remit payments only”.nj.gov, Filing and Remitting Sales and Use Tax · Sales & Use Tax Filing Chart (PDF, updated 2025) · N.J.S.A. 54:32B-17(a), (b)

New Jersey’s Monthly Voucher covers the first two months of each calendar quarter and never the third, which is reported on the quarterly ST-50. The form was formerly the ST-51 and much published material still calls it that; the Division’s 2026 tax calendar prints “Monthly Voucher — Formerly called the ST-51”, and its filing portal offers it only as a form type of the current name.Sales & Use Tax Filing Chart (PDF, updated 2025) · nj.gov, Filing and Remitting Sales and Use Tax · New Jersey Tax Calendar 2026 (Rev. 6/26), sales and use tax entries

Connecticut assigns one filing basis and that is the only return filed. New York and New Jersey put a monthly obligation on top of a quarterly return that never lapses. §12-414(a) assigns a filer to annual, quarterly or monthly remittance, and (b)(1) files the return for “each monthly or quarterly period, as the case may be” — there is no Connecticut analogue of Form ST-810 or Form ST-50 sitting underneath the monthly grid. The filing count hides the difference completely: all three states put a monthly-tier filer on twelve filings a year, by three different structures, so counting filings cannot tell them apart. The practical risk is not a missed filing but a Connecticut client sent looking for a quarterly return that does not exist.Conn. Gen. Stat. §12-414(a), (b)(1), (e)(1) · N.Y. Tax Law §1136 (Art. 28, Part 4) · nj.gov, Filing and Remitting Sales and Use Tax

How a business lands on each tier

The figures below decide which row of the first table a business is on. They are not comparable as written: New York’s monthly-filing threshold measures receipts, while both New Jersey figures and both Connecticut figures measure tax collected. Each label says which, and each state measures over a different window.

Getting off New York’s monthly grid is not the mirror of getting onto it. Tax Bulletin ST-275 requires a vendor to keep filing monthly until its taxable sales fall below the threshold in each of four consecutive quarters, and then permits it to “contact the Tax Department to request a change to quarterly filing status.” It is a request, not an automatic reversion: nothing obliges the Department to grant it, and a vendor who simply stops filing monthly on the strength of the fourth clean quarter is late on the fifth month. Onto the grid the duty runs the other way — Publication 750 makes it the vendor’s own responsibility to notify the Department and to file for the first month it is required to, whether or not a notice has arrived.N.Y. Tax Law §1136 (Art. 28, Part 4) · TB-ST-275 (updated November 20, 2015; page updated June 4, 2026) · Pub. 750 (11/15), pp. 33-34

New York’s annual return is not a small vendor’s election. Tax Bulletin ST-275 provides that where a quarterly filer’s total tax due for the four most recently filed quarterly periods is at or below the threshold, the Department “may reclassify you as an annual filer” and “will notify you of the change” — discretion the Department exercises, not a right the vendor can take up. Publication 750 adds the one automatic route, and it is shut to anyone who collects tax at all: a vendor is classified annual on registering only if it expects to pay or collect no sales or use tax and describes itself as a manufacturer or wholesaler that makes no retail sales.TB-ST-275 (updated November 20, 2015; page updated June 4, 2026) · Pub. 750 (11/15), pp. 33-34

A New Jersey seller owes a monthly payment only where both tests are met: sales and use tax collected in New Jersey during the prior calendar year exceeded the annual threshold, and the tax due for the first or second month of the current quarter exceeds the monthly one. The prior-year test is the gate and is answered first — a seller under it makes no monthly payment at all that year, whatever a single month produces, and the Division says so in terms: no payment is required for either month “no matter how much tax is due for that particular month”. The printable filing chart states only the monthly test in its “who must file” column and puts the prior-year condition in a footnote, which is how a small seller ends up on a grid it is not on.nj.gov, Filing and Remitting Sales and Use Tax · Sales & Use Tax Filing Chart (PDF, updated 2025)

Connecticut’s default filing basis is monthly, and the other two tiers are exceptions carved out of it. §12-414(a) makes the tax “due and payable to the commissioner monthly on or before the last day of the month next succeeding each monthly period”, then excepts a filer below the annual threshold to annual remittance and one between the two thresholds to quarterly. A Connecticut filer is therefore monthly because no exception reached it, not because the Department escalated it — the opposite direction of travel from New York and New Jersey, where quarterly is the base and a monthly obligation is added on crossing a figure. In practice the frequency is assigned: Form O-88 has returns filed “in accordance with your monthly, quarterly, or annual filing frequency assigned by the Department of Revenue Services”, and a client follows the assignment it was given.Conn. Gen. Stat. §12-414(a), (b)(1), (e)(1) · Form O-88 (Rev. 09/20), General Instructions and Due Date

Connecticut fixes the filing basis on “total tax liability for the twelve-month period ending on the preceding June thirtieth” (§12-414(a)). Two things follow: the measure is tax rather than sales, and the window closes in June, so a business whose volume changes in the autumn keeps its current basis for the rest of the year. Each of the three states uses a different clock — New York tests any one of the preceding four quarters and can fire mid-year, New Jersey a fixed calendar year, Connecticut a fixed year ending in June.Conn. Gen. Stat. §12-414(a), (b)(1), (e)(1)

A quarter with no sales

The Division: “You must file a return for each quarter even if no tax is due and/or no sales were made during the period.” The obligation attaches to holding the authority to collect rather than to having collected, so a seasonal seller — including the flea-market and craft-show sellers the Division names on the same page — files every quarter whatever the season did.nj.gov, Filing and Remitting Sales and Use Tax

Form O-88: a business must file Form OS-114 “to report all sales activity in Connecticut, even if no sales were made or no tax is due. Both taxable and nontaxable sales must be reported.” All three states agree on this, which is worth knowing precisely because most of what surrounds it is difference.Form O-88 (Rev. 09/20), General Instructions and Due Date

New Jersey requires the quarterly return to be filed empty and forbids the monthly voucher from being filed empty. The Division: ““Zero” monthly vouchers cannot be submitted”, and “A Monthly Voucher is used to remit payments only. You cannot file this form unless you have a payment to submit.” Where the month’s tax is at or below the monthly threshold no voucher is due — but the money is deferred, not forgiven: “Payment for that month must be made with the next quarterly return, Form ST-50.”nj.gov, Filing and Remitting Sales and Use Tax

Where this stops

One question this page does not answer: when a change of Connecticut filing frequency takes effect. The statute fixes the tier on liability for the twelve months ending on the preceding 30 June but does not say when a reassigned filer starts on the new basis, and no Department notice saying so was found. The reading that it begins with the period starting 1 July is a reasonable one and is not published anywhere consulted, so it is not stated here as fact. Confirm it from the assignment itself.

Myung Keon Kim CPA prepares and files sales tax returns for New York and New Jersey. Connecticut appears on this page for comparison, because a client with a New York or New Jersey shop routinely asks how the neighbouring state differs. It is not a service offered here.

Last verified: 2026-09-09