Frequently asked questions

For income tax: individuals (other than trusts) and graduated rate estates get the later of one year after the tax year's filing-due date and 90 days after the day of sending of the notice. Corporations and other trusts get 90 days after the day of sending (ITA s.165(1)).

For GST/HST: 90 days after the day the notice of assessment is sent (ETA s.301(1.1)).

The statute says "sending", not "mailing". Use the free deadline calculator to work it out from your notice date.

Day 0 is the date printed on the notice — a notice of assessment is legally presumed sent on that date (ITA s.244(14)). Counting starts the day after. Electronic notices in My Account / My Business Account have their own deemed-sent rules (s.244(14.1)–(14.2)), so confirm which date counts if your notice was electronic.

You may apply to the Minister for an extension within one year after the deadline expired (ITA s.166.1 for income tax; ETA s.303 for GST/HST). The Minister may grant or refuse it — it is discretionary — if you were unable to act or genuinely intended to object, it would be just and equitable, and you applied as soon as circumstances permitted.

If refused, or if 90 days pass with no response, you may apply to the Tax Court of Canada to have the extension granted (s.166.2 / s.304), within 90 days of the refusal notice. CRA may refuse — treat this as urgency, not a safety net.

The CRA validates your objection and assigns an appeals officer, who reviews it independently. CRA published resolution times: service standards of 180 days (low-complexity, 80% target) and 365 days (medium-complexity). Actual June 2026 averages were 127 days (low), 389 days (medium), and 690+ days (high-complexity, 2–3% of workload). Expect to wait months, not weeks.

Yes. Interest keeps accruing during the dispute on any amount owing. Paying now reduces interest even if you later win — many taxpayers pay the disputed amount and fight for it back.

Generally, yes — on the disputed amount. Filing an objection generally suspends CRA collection action on the disputed amount until 90 days after the Minister's decision notice is sent (ITA s.225.1(2)). Exceptions where collections continue include source deductions and withheld amounts (s.225.1(6)), amounts not in dispute, tax-shelter charitable-donation claims, and jeopardy collections (s.225.2). Large corporations must still pay half (see below).

Corporations (plus related corporations) with group taxable capital employed in Canada exceeding $10 million must pay half the assessed amount even while objecting (ITA s.225.1(7)–(8)). This is a flag, not advice — if it might apply to you, talk to a tax professional.

Three differences: the deadline is a flat 90 days after the notice is sent (ETA s.301(1.1)); it must be filed on the prescribed Form GST159 — not a plain letter and not Form T400A; and there is no documented fax option, so plan to mail it. Income-tax and GST/HST disputes are separate filings — do not try to combine them.

A notice of objection disputes the assessment itself — the facts and law behind how much tax you owe. A taxpayer relief request (Form RC4288) is a separate track that can only ask the CRA to cancel or waive penalties and interest; it cannot change the tax the CRA says you owe, and there is no right of objection or appeal on relief decisions. Read the full guide.

It must clearly explain what is being objected to and why, set out the reasons and all relevant facts, and include supporting documentation. The packet builder organises this per issue: what the CRA decided, the facts as you state them, the provisions in dispute, and the relief you are requesting.

No. Nyphron is a do-it-yourself document tool built by a Canadian CPA. It is not a law firm, not an accounting firm, and not your accountant. Nothing on this site is legal, tax, or accounting advice, and using the site creates no client relationship. You are solely responsible for any documents you file with the CRA.

There are no refunds. The packet is delivered instantly as a digital product, so all sales are final. You are solely responsible for the documents you file. See the terms.

If very large dollar amounts are at stake, or your dispute involves GAAR, transfer pricing, cross-border issues, or a criminal tax investigation — get professional help. A $39 DIY packet is the wrong tool for those cases.