What are the rules for Form T183 when I EFILE a client's return?
Form T183 is your client's authorization to EFILE their T1, and Part F must be signed before you transmit. You and the client keep a copy for at least six years after filing and send it only if the CRA asks. A correction moving the refund or balance owing by more than $300 needs a new T183.
What does Form T183 require before and after you transmit?
The T183 is the information return your client gives you so you can EFILE their T1. The client fills in parts A, B and F, you fill in parts C and D, and the client keeps a copy after giving you the signed original canada.ca. As of October 2026 the CRA's rules for electronic filers come down to this
canada.ca.
| Rule | What the CRA requires |
|---|---|
| Timing | Part F is signed before the return is transmitted |
| Who signs | The taxpayer, or the person required to file (trustee in bankruptcy, legal representative); a power of attorney holder only with a copy of the POA |
| Tax year | The form is year specific and must show the year you are filing |
| Copies | Completed in duplicate: the original to you, a copy to the client |
| Amounts | The T183 entries must match the electronic return |
| Correction after a rejection | New signed T183 if the refund or balance owing changes by more than $300 |
| Sending it in | Only when the CRA asks for it |
| Retention | At least six years after the return is filed, in a secure place |
| Scanned copies | Allowed if readable and the signed information is not altered |
| Electronic signature | Accepted if applied the way the CRA specifies |
The legal hook is subsection 150.1(4) of the Income Tax Act: when someone else files the return electronically, the person required to file makes an information return in prescribed form, keeps a copy and gives it to the filer, and both copies are treated as section 230 records laws-lois.justice.gc.ca. The CRA's EFILE checklist puts getting the signed T183 at step 3 and transmitting at step 5
canada.ca.
Because the form is year specific, a client catching up on back years signs one T183 per return. EFILE takes initial T1 returns for 2018 to 2025 during the transmission window that runs from February 23, 2026 to January 29, 2027 canada.ca.
When does a corrected return need a new T183?
Only when the fix moves the refund or balance owing by more than $300. By signing Part F, the client lets you correct a rejected return and transmit it again, as long as the refund or balance owing in Part B doesn't change by more than $300 canada.ca. Past that, the client completes and signs a new T183 before you send it again
canada.ca.
Say your client signed a T183 showing a refund of $1,850 on line 48400, and EFILE rejects the return for a missing slip.
| Correction before you retransmit | Refund in Part B | Corrected refund | Change | New T183? |
|---|---|---|---|---|
| A T5 adds $1,000 of interest | $1,850 | $1,620 | $230 | No |
| A missed RRSP receipt is added | $1,850 | $2,200 | $350 | Yes, signed before you retransmit |
| A wrong SIN for a dependant is fixed | $1,850 | $1,850 | $0 | No |
Measure the change against the Part B figure the client signed, not against the previous rejected attempt. The 2025 form's Part C declaration covers both a new and an amended return canada.ca, and ReFILE accepts amended T1 returns for 2022 to 2025 only
canada.ca.
Can your client sign the T183 electronically?
Yes. The T183, T183CORP and T183TRUST are all on the CRA's list of forms that accept an electronic signature, along with forms such as T2183, T2200 and CPT30, and it's the taxpayer's choice whether to sign on paper or electronically canada.ca. The signing tool can be built into your certified software or come from a third party.
You're expected to verify who signed, and the signature has to meet one of two conditions canada.ca:
| How the client signs | Condition |
|---|---|
| In person | The client signs in front of you, for example with a stylus or a finger on a tablet |
| Remotely by email | You send the form to the email address the client most recently gave you for that purpose |
| Remotely through a portal | The form sits in a secure location, such as a secure website, that the client can reach only because you gave them access |
Part F carries a signature date and time down to the second canada.ca. Keep the certificate of completion from the signing service with the signed T183: the CRA may ask for it under its monitoring program, especially when the signed form doesn't display the time stamp
canada.ca. The CRA also highly recommends masking the first five digits of the SIN on printed or software generated forms.
How does T183CORP differ for a corporate return?
The corporate version follows the same idea with a different signer and different amounts. Here are the 2025 T183 and the 2024 T183CORP, the latest versions the CRA posts canada.ca
canada.ca, side by side.
| Point | T183 (T1) | T183CORP (T2) |
|---|---|---|
| Who signs | The individual or their legal representative, Part F | An authorized signing officer, Part 3 |
| Amounts declared | Refund or balance owing, total income, taxable income, federal credits (line 35000) | Net income (line 300), each Part tax payable, total tax payable (line 770) |
| Returns covered | A new or amended T1 | Every initial and amended T2 |
| Your authority to fix errors | Retransmit if the refund or balance owing moves $300 or less | Modify the return in response to errors the CRA identifies, until the CRA accepts it |
| Sent to the CRA | Only on request | Not unless the CRA asks |
| Client's copy | Kept by the client | Kept by the corporation for six years |
| Electronic signature | Accepted | Accepted |
The T183CORP authorization expires when the Minister accepts the electronic return as filed, and the signing officer also certifies that the method of calculating income matches the previous year unless a statement says otherwise canada.ca. For tax years starting after 2023, every corporation files its T2 electronically except insurance corporations, nonresident corporations, those reporting in a functional currency and those exempt under section 149
canada.ca. Deadlines are on the T2 filing deadline page.
What happens if the CRA asks for your T183s and you cannot produce them?
Your EFILE privileges can be suspended. The CRA periodically asks each electronic filer for a number of T183 copies and may ask for written explanations of errors it finds, and it can suspend you if you don't provide them within its deadline canada.ca. Late, missing, illegible or incomplete T183 forms are also a listed ground for revoking your authorization to EFILE.
A warning letter usually comes first, but some cases allow suspension immediately, without warning and without the possibility of reinstatement. A suspended filer can ask for an administrative review in writing within 90 days of the notice date canada.ca.
When someone other than the taxpayer signed, send proof of their authority with the requested T183s. A legal representative for a deceased client gives you a copy of the death certificate, a POA holder gives you a copy of the power of attorney, and you attach it to the T183 and keep it at least six years after the return was filed canada.ca. The return itself is covered on the final return for a deceased person page.
How long do you keep the T183, and can it be a scan?
Keep your copy in a secure location for at least six years after the return is filed, and don't destroy it sooner without written permission canada.ca. Scanned copies are fine if they meet section 230 of the Income Tax Act, including a minimum resolution in an electronically readable format, and storage doesn't change the signed information.
Your client has the same obligation on their side: by signing Part F they acknowledge they must keep all the records used to prepare the return for six years and give them to the CRA on request canada.ca. The general six year clock, and the cases where it runs longer, are on the CRA record retention page.
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Can I transmit the return and get the T183 signed afterward?
Do I send the T183 to the CRA with the return?
Can a family member sign the T183 for my client?
Only with a power of attorney. Someone other than the taxpayer, trustee or legal representative can sign if an applicable POA exists, and you keep that POA with the T183 for at least six years after the return was filed canada.ca.
Am I required to EFILE in the first place?
Yes, if you prepare returns for a fee. Under 150.1(2.3), a tax preparer files those returns electronically, with up to five individual, five corporate and five trust returns allowed another way laws-lois.justice.gc.ca. Getting set up is covered on the EFILE registration page.
General information for the tax year shown, not advice for a specific client. Confirm the facts before you file or remit.