There is no CRA form called the T20 tax form. Taxpayers searching that term almost always need the T652, Notice of Revocation of Waiver, which cancels a T2029 waiver you previously filed to give the Canada Revenue Agency extra time to reassess a specific tax year.1Canada Revenue Agency. T652 Notice of Revocation of Waiver Once the CRA receives your T652, it has six months to finish any reassessment for that year and issue. After that window closes, the door closes permanently.2Department of Justice Canada. Income Tax Act – Section 152
What the T652 Actually Does
The CRA can normally reassess a return only within a set window. For individual taxpayers and Canadian-controlled private corporations, that window is three years from the date of the original notice of assessment. For mutual fund trusts and corporations that are not Canadian-controlled private corporations, the window is four years.2Department of Justice Canada. Income Tax Act – Section 152 After that, the year is statute-barred and generally untouchable.
A T2029 waiver keeps the window open past the normal period for a specific matter — a disputed deduction, a pending ruling, a credit application that requires the year to stay live.3Canada Revenue Agency. T2029 Waiver in Respect of the Normal Reassessment Period or Extended Reassessment Period The waiver runs indefinitely. The T652 is how you shut it off.
How the Six-Month Clock Works
The rule sits in subsection 152(4.1) of the Income Tax Act. When the CRA receives your T652 in the prescribed form, it has six months from that date to issue any reassessment, additional assessment, or assessment of tax, interest, or penalties tied to the matter your original waiver covered.2Department of Justice Canada. Income Tax Act – Section 152 Silence for six months means the CRA loses the authority to act.
The receipt date is the whole ballgame. You need documented proof of when your T652 arrived, because that date starts the clock. Registered or certified mail gives you delivery confirmation. If you file through My Account or Represent a Client, save the system’s confirmation. Without proof of the filing date, arguing the six months have run is much harder.
Revocation is not retroactive. If the CRA already issued a reassessment before your T652 landed, that reassessment stands. The form only forecloses future action on the covered matter.
Information You Need on the Form
The T652 is short, but every field has to line up with the original waiver. An incomplete or mismatched filing can delay the clock or get rejected.
- Taxpayer identification: your Social Insurance Number for individual filings, or a nine-digit Business Number for corporations.
- Taxation year: the specific year your T2029 applies to.
- Description of the matter: this must match the description on the original T2029 word for word. If the waiver covered investment tax credits, your T652 must reference investment tax credits, not a vague or broader description. Ambiguity gives the CRA room to argue the revocation doesn’t reach the issue it wants to reassess.
- Signature: an individual taxpayer signs personally. A corporation signs through an authorized officer. A representative filing on your behalf must already have authorization on file with the CRA, such as through Form AUT-01.4Canada Revenue Agency. Authorize a Representative for Offline Access
Pull your copy of the original T2029 before you start. You need the exact matter description, the taxation year, and the signing date. The T652 itself is a fillable PDF on the CRA’s forms page.1Canada Revenue Agency. T652 Notice of Revocation of Waiver
How to Submit the T652
Mail your completed form to the Tax Services Office or Tax Centre that handles your file. The CRA routes processing by postal code. Registered or certified mail is the sensible default because the tracking record fixes the receipt date, and the receipt date starts your six months.
For digital submission, individuals can use My Account and authorized tax professionals can use Represent a Client.5Canada Revenue Agency. Submit Documents Online Keep the completed form and any delivery or upload confirmation.
Filing From Outside Canada
Non-residents with Canadian tax obligations should send the T652 to the Winnipeg Tax Centre, which handles non-resident accounts:
Winnipeg Tax Centre
Post Office Box 14001, Station Main
Winnipeg MB R3C 3M3
Canada
Because international mail runs slow, the CRA has also been accepting certain non-resident filings by fax at 204-984-5164.6Canada Revenue Agency. Where to Mail Your Paper T1 Return Confirm on the CRA site that the fax option is still available before you rely on it; it was introduced as a temporary measure for international mail delays.
When Revoking the Waiver Won’t Protect You
The six-month cutoff in subsection 152(4.1) applies only where the CRA’s authority to reassess rests on your waiver. If the agency has another legal basis to reassess the year, the T652 doesn’t touch it.
The main exception is fraud or misrepresentation. Under subsection 152(4)(a)(i), the CRA can reassess at any time, with no limitation period, if the taxpayer made a misrepresentation due to neglect, carelessness, or willful default, or committed fraud in filing the return or supplying information.2Department of Justice Canada. Income Tax Act – Section 152 Revoking your waiver does not shield you from that authority. If the CRA believes the original return contained a careless or deliberate error on the same issue your waiver covered, it can still pursue reassessment under the misrepresentation rule.
Other openings the T652 doesn’t close include carryback adjustments (such as applying a current-year loss to a prior year) and certain late-filed elections. These sit outside the waiver framework, so revocation has no effect on them.
Timing Considerations Before You File
Revocation isn’t automatically the right move. If the CRA appears close to resolving an audit in your favor — dropping a proposed reassessment or accepting your position on a deduction — filing the T652 too early can backfire. A hard six-month deadline can pressure the agency to issue the reassessment it was otherwise ready to shelve, simply because the clock forces a decision.
The opposite situation is where the T652 earns its keep. A file that has sat open for years with no movement gives the CRA no reason to prioritize your case. Revocation forces a resolution one way or the other inside six months.
If the amounts are significant, or if the CRA has raised any concern about misrepresentation, talk to a tax professional before filing. The T652 does nothing to blunt the CRA’s authority under the fraud and misrepresentation rules, and filing one during an inquiry into carelessness can read as an attempt to shut the inquiry down, which tends to raise scrutiny rather than end it.
A Note for U.S. Taxpayers
If you claimed a U.S. foreign tax credit for Canadian taxes paid, any CRA reassessment that changes your Canadian liability triggers what the IRS calls a foreign tax redetermination, which usually requires recalculating your U.S. tax and reporting the change.7Internal Revenue Service. Foreign Tax Credit
Reporting runs through Form 1116, Schedule C, identifying the redetermination, the affected year, and the adjusted foreign tax. If the change moves your U.S. tax, you may also need Form 1040-X or Form 1120-X. When the redetermination doesn’t change U.S. tax, you can attach Schedule C to the return for the year the redetermination occurs rather than amending the earlier year. Failing to notify the IRS carries a penalty unless you can show the failure was due to reasonable cause and not willful neglect.8Internal Revenue Service. Instructions for Form 1116 Filing the T652 is what starts the CRA’s six-month clock, and how that clock ends determines whether you face a redetermination on the U.S. side.