How to Catch Up on Years of Late GST/HST Returns Without Losing Your Input Tax Credits
Behind on GST/HST returns? The order to file them, how late penalties work per period, the 4-year input tax credit limit, and why nil returns still count.
To catch up on late GST/HST returns, file every missing period, oldest first, using reconciled books. Claim input tax credits in the correct periods before the general four-year limit runs out, and file nil returns for periods with no activity. Each late period has its own penalty (1% of the amount owing plus 0.25% per month, up to 12 months), so the sooner they're in, the better.
Why order matters
Each return is matched against your reporting periods. Filing the newest year first leaves older periods open to arbitrary assessments and stops credits from flowing to the periods where they belong. Work oldest to newest.
The input tax credit clock
Most small businesses have four years from the due date of the return for the period the ITC relates to (canada.ca, ITC time limits). If you're five years behind, credits for the oldest year may already be gone, even though you still owe the tax you collected. That's the cost of waiting.
Step by step
- Pull your GST/HST account in My Business Account (or through your representative) to see which periods are open and whether any were assessed arbitrarily.
- Confirm your filing frequency. Growing businesses often get moved from annual to quarterly once taxable supplies pass $1.5M.
- Reconcile sales by period. Use payout reports (Stripe, Shopify, Square), not just deposits, so refunds and fees are captured.
- Separate the tax. Make sure GST/HST collected isn't booked as revenue.
- File, then pay or arrange. If you can't pay everything, set up a payment arrangement.
Example (hypothetical)
An Ontario online coaching business crossed $30,000 in 2022, registered late in 2023, and hasn't filed since. It grew to about $700k. It owes HST from the date registration was required, not the date it registered. See backdating a GST registration. Twelve quarterly returns are rebuilt and filed together, with a VDP application if the CRA hasn't been in touch.
Nil returns are not optional
A registrant files a return for every period, even with zero sales. Missing nil returns still leads to non-filer letters.
How we handle it
Sansar does GST/HST, PST and income tax catch-up as one job for one all-inclusive flat rate, backed by our 100% Happiness Guarantee. See late tax filing, the main-site business tax filing service, and our sales tax audit guide.
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FAQ
Can I file several years of GST/HST returns at once? Yes. Each period is filed separately, but they can all go in on the same day once the books are done.
What is the penalty for a late GST/HST return? 1% of the amount owing plus 0.25% of it for each full month late, up to 12 months, plus daily compound interest.
Do I lose input tax credits if I file late? You lose ITCs that fall outside the time limit, generally four years for small businesses. Credits inside the limit can still be claimed.
Do I have to file if I had no sales? Yes. A registrant files a nil return for each period with no activity.
What if the CRA already assessed my GST/HST? Filing the actual returns usually replaces the estimated assessment. If the objection deadline is close, file a notice of objection too.
Written by Gurdeep Sangha, founder of Sansar Solutions, a Vancouver-based bookkeeping and tax firm serving small businesses across Canada (mainly Ontario, Alberta and BC). Sansar is not a CPA firm; Notice to Reader and review engagements go through partner CPAs. This guide is general information, not tax or legal advice for your situation. Last reviewed: October 2026.