If you file GST/HST quarterly, your return for July, August and September is due on October 31. This year October 31 is a Saturday, and the CRA treats a return or payment as on time if it receives it on the next business day, so you have until Monday, November 2, 2026. If you file annually and pay instalments, your third-quarter instalment shares the same date.
This checklist covers what to pull together before you file, with the parts that trip up trades contractors in particular: tax on invoices that have not been paid yet, tax on holdback, and the input tax credits you can claim on materials.
Who files a Q3 return
The CRA assigns your reporting period based on your annual taxable supplies (your revenue that GST/HST applies to). You can choose a more frequent period than the one assigned to you.
| Annual taxable supplies | Assigned period | You can choose |
|---|---|---|
| $1,500,000 or less | Annual | Quarterly or monthly |
| More than $1,500,000 up to $6,000,000 | Quarterly | Monthly |
| More than $6,000,000 | Monthly | No other option |
Quarterly and monthly returns are due, with any payment, one month after the end of the period. For a calendar-quarter filer, the July-to-September return is due October 31. Electronic filing is mandatory for almost every GST/HST registrant; paper returns draw a penalty.
Annual filers: your Q3 instalment
If you file annually and your net tax was $3,000 or more last year and will be $3,000 or more this year, you pay GST/HST in quarterly instalments. Each one is due one month after the end of a fiscal quarter. With a December 31 year-end, that is April 30, July 31, October 31 and January 31. Each instalment is usually one quarter of last year’s net tax.
Not registered for GST/HST because you are a small supplier? Then there is nothing to file. Just keep an eye on your revenue against the $30,000 line with our GST/HST threshold tracker.
The pre-filing checklist for trades contractors
1. Count tax on invoices you sent, paid or not
GST/HST becomes payable on the earlier of the day you are paid and the day the money becomes due, and it becomes due on the date of your invoice. In practice: the tax on every invoice dated in July, August or September belongs on your Q3 return, even if the customer has not paid you yet. It is easy to miss if you think about your books in terms of money in the bank.
2. Check how your invoices handle tax on holdback
Holdback has its own rule, and which way it goes depends on your invoices. When a customer holds back part of the price under provincial law or a written construction contract, the GST/HST on the held-back amount becomes payable on the earlier of the day it is paid to you and the day the holdback period expires.
That matters if your progress invoices do not charge tax on the held-back portion: the tax on it then belongs on the return for the period it is released, not the quarter you invoiced. But if your invoice charged GST/HST on the full amount, holdback included, that tax goes on the return for the period of the invoice like any other tax you charged. Markup invoices work the second way: holdback is taken off the pre-tax amount and GST/HST is charged on the full amount, so the tax is reported with the invoice. Either way, track your holdback separately so you know what is still owed to you.
3. Claim your input tax credits, with the paperwork
The GST/HST you paid on materials, tools, fuel, rentals and subcontractors used in your business comes back to you as input tax credits (ITCs). To support the claim, keep the supplier’s invoice. For purchases of $100 or more it must show the supplier’s GST/HST registration number; for $500 or more it also needs your name, a description and the payment terms.
4. Check your subcontractors’ GST/HST numbers
If a sub charged you GST/HST, confirm their registration number is valid before you claim it back. The CRA runs a free GST/HST registry for exactly this. An invalid number can cost you the ITC.
5. Match the tax to the job site’s province
If you worked across a provincial line this quarter, check that each invoice charged the right rate for where the work was done. Our sales tax calculator covers every province and territory.
If you file late
A late GST/HST return with a balance owing draws a penalty of 1% of the amount owing, plus 0.25% of the amount owing for each full month the return is late, up to 12 months. Interest is charged on top, at the CRA’s prescribed rate, compounded daily from the day after the due date. On $8,000 owing, a return filed three full months late costs $80 plus $60, before interest.
If you cannot pay in full, file on time anyway. The late-filing penalty is separate from interest on the unpaid balance, and filing on time avoids it.
Want every CRA date for your province and filing frequency in one place? Use the free CRA deadline calendar.
Sources
- CRA: Reporting requirements and deadlines
- CRA: Find out if you need to pay GST/HST by instalments
- CRA: Time of Liability (GST/HST Memorandum 300-6)
- CRA: GST/HST and home construction (holdbacks)
- CRA: Instructions for preparing a GST/HST return
- CRA: Documentary requirements for claiming ITCs
- CRA: GST/HST filing penalties
This article is general information, not tax advice. Check your own situation with your accountant or the CRA.