Where to mail a T1 adjustment request (form T1-ADJ)
Mail your T1 adjustment request — form T1-ADJ or a signed letter — to your own tax centre: the Winnipeg Tax Centre (PO Box 14001, Station Main, Winnipeg MB R3C 3M3) for the West and territories, the Sudbury Tax Centre for most of Ontario and Atlantic Canada, or the Jonquière Tax Centre for most of Quebec. The routing is identical to paper T1 returns, so use the card below that matches where you live.
Winnipeg Tax Centre
Winnipeg Tax Centre Post Office Box 14001, Station Main Winnipeg MB R3C 3M3
Residents of AB, BC, MB, SK, NT and YT, plus the Ontario cities of Hamilton, Kitchener, Waterloo, London, Thunder Bay, and Windsor
Sudbury Tax Centre
Sudbury Tax Centre 1050 Notre Dame Avenue Sudbury ON P3A 5C2
Residents of NB, NL, NS, NU and PE; the Ontario cities of Barrie, Belleville, Kingston, Ottawa, Peterborough, St. Catharines, Sudbury, and Toronto; and the Quebec regions of Montréal, Outaouais, and Sherbrooke
Jonquière Tax Centre
Jonquière Tax Centre 2251 René-Lévesque Boulevard Jonquière QC G7S 5J2
Residents of Quebec outside the Montréal, Outaouais, and Sherbrooke regions
Mail it without printing anything
Upload your document — we print it, seal it, and deposit it with Canada Post within 24 hours on business days. $6 flat, no account needed, and you get a Confirmation of Mailing email for your records.
Key facts
- A T1 adjustment goes to the same tax centre as your paper T1 return — Winnipeg, Sudbury, or Jonquière, depending on where you live.
- You can use form T1-ADJ or a signed letter that states the tax year, your social insurance number, and the exact change you are requesting.
- Attach supporting documents — slips, receipts, or schedules — for every change you request; the CRA cannot process an adjustment it cannot verify.
- Mailed adjustments take roughly 8 weeks to process, compared with about 2 weeks for changes submitted online through CRA My Account.
- PostPal prints and mails your T1-ADJ for $6 flat, deposited with Canada Post the next business day — no printer or account needed.
How to mail it, step by step
- 1
Fill out form T1-ADJ or write a signed letter
Form T1-ADJ is the cleanest option: one form per tax year, with the line numbers you want changed, the previous amounts, and the revised amounts. A signed letter works too, as long as it includes your SIN, address, the tax year, and the details of each change.
- 2
Gather your supporting documents
Include copies of any slips, receipts, or schedules that back up the change — for example a late T4, a missed donation receipt, or a corrected RRSP slip. Keep the originals; mail copies only.
- 3
Find your tax centre
Winnipeg serves the West, the territories, and six southwestern Ontario cities. Sudbury serves Atlantic Canada, the rest of Ontario, and the Montréal, Outaouais, and Sherbrooke regions of Quebec. Jonquière serves the rest of Quebec. The split is exactly the same as for paper T1 returns.
- 4
Mail it and wait for your notice of reassessment
Paper adjustments take about 8 weeks to process. Upload your T1-ADJ and supporting documents to PostPal and we print, envelope, and hand them to Canada Post within one business day — $6 flat, no account needed.
Common questions
Where do I mail form T1-ADJ?
To your own tax centre — the same one that handles your paper T1 return. That is the Winnipeg Tax Centre (PO Box 14001, Station Main, Winnipeg MB R3C 3M3) for the West and territories, the Sudbury Tax Centre (1050 Notre Dame Avenue, Sudbury ON P3A 5C2) for Atlantic Canada and most of Ontario, or the Jonquière Tax Centre (2251 René-Lévesque Boulevard, Jonquière QC G7S 5J2) for most of Quebec.
Do I need form T1-ADJ, or can I just send a letter?
Either works. The CRA accepts form T1-ADJ or a signed letter that gives your social insurance number, address, the tax year, and the exact changes you want — including the line numbers and revised amounts where possible. The form keeps everything organized, which can speed up processing.
How long does a mailed T1 adjustment take?
Plan on roughly 8 weeks for a mailed adjustment, versus about 2 weeks if you submit the change online through CRA My Account. Complex requests or missing documents can take longer. The CRA sends a notice of reassessment (or a letter explaining why no change was made) when it is done.
What documents should I include with my adjustment request?
Copies of everything that supports the change: the missing or corrected slip, receipts for a new deduction or credit, and any revised schedules. Do not send originals. An adjustment without supporting documents will usually be delayed or denied.
I live in Montréal — do I mail Jonquière or Sudbury?
Sudbury. Residents of the Montréal, Outaouais, and Sherbrooke regions send their T1 adjustments to the Sudbury Tax Centre, 1050 Notre Dame Avenue, Sudbury ON P3A 5C2. The Jonquière Tax Centre handles the rest of Quebec.
Can I adjust more than one tax year in the same envelope?
Yes, but use a separate T1-ADJ (or a clearly separated section of your letter) for each tax year, with that year’s supporting documents attached. You can generally request changes for any of the 10 previous calendar years.
Sources
Addresses verified June 2026 against official sources. Always confirm on the official site before time-sensitive filings.