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GST/HST Post-Assessing Review: What It Is and How to Respond

Updated 4 min read HST in Canada
On this page
  1. Post-assessing review vs audit
  2. Common reporting errors that may need adjusting
  3. Read and verify the request
  4. Assemble a response
  5. What happens next?
  6. If you disagree

A GST/HST post-assessing review (also called a post-assessment review) is a CRA check of specific amounts on a return it has already assessed. It is not an audit: CRA may ask for an explanation or the documents behind those amounts and may adjust the return.

Post-assessing review vs audit

CRA checks specific amounts on a return already filed — for example, a mismatch between the sales reported and the GST/HST collected on those sales, or between the GST/HST return and the income tax return — and may ask you to explain the amounts or provide supporting documents such as receipts or invoices. CRA describes a post-assessing review as neither an audit nor a “books and records” review. CRA: GST/HST Post Assessing Review

An audit goes further. A CRA auditor usually works from the books and records, normally at the place of business — though the auditor may ask for electronic records first if available, which can reduce time spent there — may ask for related personal or business records, and can use indirect methods such as the net worth method to verify income. CRA: business audits

Common reporting errors that may need adjusting

CRA’s review process looks at amounts reported on different lines of a GST/HST return, or compares the GST/HST return to the income tax return for the same business, to uncover discrepancies. CRA lists these as common reporting errors that may need to be adjusted:

  • Switching the GST/HST collected and the input tax credit (ITC) amounts between lines.
  • Missing a digit, or missing the cents, when entering sales and revenue.
  • Entering the same figure for GST/HST collected and for ITCs.
  • Entering only the net tax amount instead of the GST/HST collected.

CRA may notify you by letter, by email asking you to check your CRA business account, and sometimes with a follow-up phone call. CRA: GST/HST Post Assessing Review

Read and verify the request

If CRA calls about your GST/HST return or sends a review letter, identify the RT account, reporting period, items under review, the requested documents, reference number and any response date in the correspondence. If a caller or message is unexpected, use the independently published CRA business contact route to verify it before disclosing account details. Ask the responsible CRA contact promptly if you cannot meet a stated deadline. CRA: contact about a GST/HST return

Assemble a response

  1. Locate the filed return and the calculation or reconciliation for the period.
  2. For each amount questioned, connect the return line to the relevant records. For an input tax credit, gather the supporting invoices or receipts and an explanation of the eligible commercial-use portion where applicable.
  3. Provide the documents requested, organized with the reference number and an explanation of any difference. If a record is missing, explain that to the CRA contact instead of inventing a replacement.
  4. Follow any instructions in the request; CRA business accounts offer a Submit documents service. Keep copies, proof of submission and any follow-up correspondence. CRA: GST/HST records and reviews, CRA: submit documents

For example, if CRA asks about a $130 ITC, supply the invoice and the calculation showing how the amount claimed relates to eligible business use; the invoice alone does not establish every eligibility condition. CRA: ITC records

Post-assessing review, step by step:

  1. CRA contacts you by letter, by email asking you to check your CRA business account, or with a follow-up phone call. Verify any caller through the published CRA business contact route.
  2. You gather what the letter asks for — for example, an explanation of the queried amounts or supporting documents such as receipts or invoices.
  3. You send the response as the letter instructs; CRA business accounts offer a Submit documents service.
  4. CRA accepts the figures as filed or adjusts the return; a notice of assessment or reassessment follows when a refund is owed or the amount owing is more than what was paid.
  5. If you disagree, file a formal objection within 90 days after the notice was sent.

What happens next?

CRA does not state how much longer a return selected for further review may take beyond its standard processing time. Respond by any date stated in the CRA’s request; if you need more time, contact the CRA before then using the details in that correspondence. CRA may accept the information or adjust the return. Review any resulting notice, including the reporting period, explanation, balance, interest and payment deadline. An assessment is not always a bill: depending on the return it can also show a refund. CRA says refunds may be delayed by incomplete or incorrect information, and it may hold a refund when required returns or amounts remain outstanding. CRA: after filing

If you disagree

An adjustment request corrects your own filed figures. A formal objection challenges an assessment or reassessment. The GST/HST objection normally must be filed within 90 days after the notice was sent. CRA accepts an electronic objection through its account services or a mailed notice such as Form GST159; set out the facts, reasons and supporting documents. Do not assume an informal discussion or adjustment request pauses the objection deadline. CRA: GST/HST objections

For personal income tax, see the normal reassessment period. If your GST/HST account is administered by Revenu Québec, follow the instructions from the authority handling that account.

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