How do I file T4 slips and the T4 Summary online, and do I need a web access code?
To file the 2026 T4 Summary online, use the CRA's Web Forms for up to 100 slips, or Internet file transfer for an XML file of up to 150 MB. Sign in with the payroll account number and web access code, or through My Business Account or Represent a Client. More than five slips must be filed electronically.
Web Forms or Internet file transfer: which one fits your client?
The CRA takes T4 returns online two ways: Web Forms, its own free form, and Internet file transfer (IFT), which uploads an XML file your payroll software builds canada.ca. Both carry the slips and the T4 Summary together. CDs, DVDs and USB keys are not accepted.
| Web Forms | Internet file transfer (XML) | |
|---|---|---|
| Best for | A small payroll keyed by hand | Payroll software that exports XML |
| Limit | Up to 100 slips per submission | 150 MB per file, 1 GB uncompressed |
| Who builds the XML | Web Forms, as an encrypted file | Your software, to the CRA schema |
| T4 Summary totals | Calculated for you | Must be in the file |
| Errors | Checked as you type each slip | Checked when you upload |
| Proof the CRA got it | Confirmation of receipt page | Submission number |
| Cost | Free | Free to file; the software is yours |
Each IFT submission needs a T619 Electronic Transmittal record, and since January 2025 every return in one submission must be the same information return type canada.ca. An XML file saved from Web Forms, or a PDF renamed to .xml, won't pass IFT validation
canada.ca. A compressed upload can hold only one XML file, and that file can't exceed 1 GB once uncompressed
canada.ca. Web Forms also warns you not to reuse a submission filed in 2025 or earlier, so build 2026 slips fresh rather than importing last year's file.
There's a grouping rule that decides the method for a larger payroll. The CRA wants slips of the same type, tax year and account number grouped under one summary and filed as one return canada.ca. Past 100 T4 slips, that return no longer fits in Web Forms, so it goes by IFT.
How do you sign in: web access code or a CRA login?
To open Web Forms or IFT directly, you need the 15 character payroll account number (the RP account for T4 slips) and the web access code linked to it canada.ca. The code is case sensitive. Sign in through My Business Account or Represent a Client and you don't need it at all
canada.ca.
| Route | What you sign in with | Fits |
|---|---|---|
| Direct to Web Forms or IFT | Payroll account number plus web access code | A client who files their own slips, or a firm without online authorization |
| My Business Account | The owner's CRA sign in, no web access code | The business owner or an employee with access |
| Represent a Client | Your RepID sign in, no web access code | An accountant authorized on the payroll account |
To get or replace a lost web access code, use the CRA's online Web access code service or call business enquiries at 1 800 959 5525 canada.ca. If your client runs more than one payroll account, each account gets its own return. Setting up the authorization for your firm is covered in Represent a Client authorization.
Whichever door you use, the T619 has to match it. Sign in with My Business Account and the T619 carries the same business number; sign in with Represent a Client and it carries your RepID; sign in with a web access code and only a full 15 character account number works canada.ca. A mismatch rejects the whole file.
Which of three clients must file online, and what would paper cost?
The five slip rule is in Income Tax Regulations 205.1(1): a return type must be filed electronically when more than five returns of that type are required for the year laws.justice.gc.ca. The count runs per type, and the penalty for filing on paper anyway is a flat amount under ITA 162(7.02)
laws-lois.justice.gc.ca.
| Client | Slips for 2026 | Must file online? | Method | Cost if mailed on paper |
|---|---|---|---|---|
| A, a dental office | 4 T4 and 3 T4A | No: 4 and 3 are each five or fewer | Paper or Web Forms | Nil |
| B, a restaurant | 12 T4 | Yes: 12 is more than 5 | Web Forms (12 is under 100) | $125 (6 to 50 slips) |
| C, a contractor | 140 T4 | Yes: 140 is more than 5 | IFT (140 is over the 100 slip Web Forms cap) | $250 (51 to 250 slips) |
Client A has 7 slips in all, but 4 + 3 isn't how the rule counts: each type stands alone, so both can go on paper. Client B's $125 is a flat charge for using the wrong format, separate from any late filing penalty. Client C can't split 140 slips across two Web Forms returns without breaking the one summary grouping, so the payroll software's XML export is the route.
The late filing penalty and the due dates sit in the T4 slip deadline. What each summary line means is in the T4 Summary.
What proves the CRA received the return?
Web Forms ends on a confirmation of receipt page, and the CRA tells you to print or save it as proof of submission canada.ca. Before you close the page, save the PDF of the return, download the individual slips for employees, and save the XML for future import if you'll need to amend.
IFT gives you a submission number on screen, but a submission number does not mean the return was accepted canada.ca. Most submissions have been validated in real time since January 2025. A large file goes to offline validation instead, and the result goes to the email address in the T619.
| What you see | What it means | What you do |
|---|---|---|
| Submission number | The CRA received the file | Keep it with the file |
| Return In progress | Still being processed | Don't resubmit it |
| Return rejected | Not filed | Correct and refile only that return |
| Whole submission rejected | Nothing filed | Fix the file and resubmit all of it |
Watch the Confirmation of Receipt email and its submission filing report, because one submission can hold accepted and rejected returns canada.ca. A rejected return refiled after the due date can draw the late filing penalty. Once a return is filed online, you can generally view it in My Business Account or Represent a Client within four business days
canada.ca.
Which errors get a T4 file rejected?
The CRA's list of common errors covers most rejections, and the schema check shows only the first error, so you fix one, resubmit and repeat canada.ca.
| Error | Fix |
|---|---|
| T619 account doesn't match the sign in | Use the business number or RepID you signed in with |
| Wrong program account | Use the RP account for T4 slips; the summary and slips must carry the same number |
| Account inactive | Confirm the payroll program account is active |
| Blank optional tags or shortcut tags | Remove them; one blank tag rejects the whole file |
| A bare ampersand or less than sign in a name | Replace it with the XML escape code |
| Decimals like .0 | Use two decimals with a leading digit, such as 0.00 |
| No SIN for an employee | Enter nine zeros |
| More than one return type | Split the file by type |
| A zip with two XML files | One XML file per zip |
| Missing T619 | Add it |
Warnings can be bypassed; bypassed errors get the affected returns rejected canada.ca. For XML problems you can't solve, the CRA's Electronic Media Processing Unit is at 1 800 665 5164
canada.ca.
Sources
Do I also mail the paper T4 Summary after filing online?
No. If you file T4 returns electronically, the CRA says you must not send a paper copy of the slips or the T4 Summary canada.ca. The summary totals are already part of the electronic return.
Can I amend or add T4 slips online without a web access code?
Yes. Through My Business Account or Represent a Client you can add, amend or cancel T4 slips without a web access code; Web Forms and IFT accessed directly still need one canada.ca. Report type codes and what goes on the amended summary are in amending a T4.
Is the due date different when I file online?
No. Online or on paper, the return is due the last day of February after the year, moved to the next business day when that falls on a weekend; the 2025 slips were due March 2, 2026 canada.ca. The 2026 date is worked out in the T4 slip deadline.
Can I email the employee copies instead of printing them?
Yes, with the employee's written consent first. A secure employer portal also works if employees can print from it, and anyone who asks for paper gets paper canada.ca. Either way, employees get their slips by the same last day of February.
General information for the tax year shown, not advice for a specific client. Confirm the facts before you file or remit.