Quick answer: Most GST/HST review letters follow a refund claim, which the CRA verifies before paying. Send the records behind your input tax credits: compliant supplier invoices and proof the tax was paid. The refund is released once the support is accepted.
A held refund is your money waiting on a reply. We handle GST/HST reviews, and the response is usually documents you already have.
A GST/HST review is answered with the working papers behind the return, not with the return itself. How these are answered, or start with an enquiry.
On this page
Why refund returns get reviewed
Refund returns are checked far more often than those with a balance owing. Classic triggers: a first refund, an unusually large one, or a new registrant claiming input tax credits on startup costs. None implies wrongdoing, but the refund waits until the review closes.
What the documentation rules actually require
Input tax credits live or die on supplier paperwork. The invoice must meet the rules for its size, chiefly showing the supplier’s GST/HST registration number; a missing number or unregistered supplier is the most common reason for denial. Our ITC guide covers each requirement.
Respond in this order
- Match each input tax credit in the period to its invoice before sending anything, so you know if one is weak.
- Verify supplier registration numbers on the CRA’s public GST/HST registry, a thirty-second check that pre-empts the most common denial.
- Send invoices plus proof of payment, organized by line, quoting the reference number, through the channel the letter names.
- If one credit cannot be supported, concede that one rather than let it hold the rest of the refund.
While the review is open
File the next period on time; an open review is no excuse, and the filing deadlines keep running. If cash depends on the held refund, respond fast and completely: response quality, not phone calls, moves the queue.
A GST review is a request for the detail behind a figure, so the response is only as fast as books that can answer a GST question on demand.
General information, not tax advice. A letter’s own wording and dates govern — confirm anything that affects a decision by sending us an enquiry.
If the review becomes a full audit, what to expect in a GST/HST audit sets out what comes next.
Common questions about GST/HST review letter
How long until my refund is released?+
Can they deny credits for someone else’s bad invoice?+
Do I keep charging and filing GST/HST during the review?+
What if I already spent the refund I expected?+
Other CRA letters, decoded
Not sure which letter you have? Start with the full list and match what yours says.
One letter often follows another. These cover the ones owner-managers see most.