The T4 Summary, form T4SUM, is the one-page total of every T4 slip you issued from one payroll account for a calendar year: employment income, CPP contributions, EI premiums and income tax deducted. You file it with the slips by the last day of February. The line that trips most employers up is line 82, because the remittances you sent the CRA during the year have to agree with the deductions totalled on line 80.
Everything below comes from the CRA's T4 Summary page for employers and its pages on when and how to file information returns, as of October 2026. Amounts are in Canadian dollars.
What the summary is for
The CRA describes the T4 Summary as the total of the information on all the T4 slips you prepared for each employee in the calendar year. The slips tell each employee what they earned; the summary tells the CRA what the whole payroll account added up to, so it can check that against what you remitted.
- Fill out a separate T4 Summary for each payroll account.
- The totals have to agree with the totals of all the slips for that account.
- Report everything in Canadian dollars, even if you paid in another currency.
- If you've no amounts to report on a slip or summary, you don't send either.
- Don't use the summary to change your address: the CRA has a separate process for account changes.
Paid anyone in another currency?
The CRA says to convert foreign currency amounts generally at the Bank of Canada exchange rate in effect on the day the amount arose. It will accept a rate from another source if that rate is widely available, verifiable, published by an independent provider on an ongoing basis, recognized by the market, used under well-accepted business principles, used for any financial statements and used consistently from year to year. Bloomberg L.P., Thomson Reuters Corporation and OANDA Corporation are sources it generally accepts.
The lines, in order
| Line | What goes there |
|---|---|
| Top of form | The last 2 digits of the year, your 15-character payroll account number (for example 123456789RP0001), legal and operating name, address |
| 88 | Total number of T4 slips you're filing |
| 14 | Total employment income, from box 14 of all slips |
| 20 and 52 | Total RPP contributions and total pension adjustments |
| 16 and 16A | Employees' CPP and, for 2024 and later, second CPP (CPP2) contributions |
| 27 and 27A | Your employer share of CPP and CPP2 |
| 18 and 19 | Employees' EI premiums, and your employer EI premiums |
| 22 | Total income tax deducted |
| 80 | Total deductions: lines 16, 27, 18, 19 and 22, plus 16A and 27A for 2024 and later |
| 82 | What you remitted to the CRA for the account in the year |
| 84 or 86 | Overpayment or balance due |
| 74 to 78 | SINs of proprietors or principal owners, and a contact person |
An authorized person signs and dates the certification at the bottom.
Making line 80 and line 82 agree
This is where the summary earns its keep. Line 80 is what your slips say you deducted and owed as the employer; line 82 is what you paid over during the year, which you can take from your most recent PD7A statement. Subtract 82 from 80:
- Negative result: you've overpaid. Enter it on line 84, and attach a note explaining why and whether you want it refunded or moved to another account or year.
- Positive result: there's a balance due. Enter it on line 86.
- No difference: leave lines 84 and 86 blank.
The CRA generally doesn't charge or refund a difference of $2 or less, as of October 2026. Anything bigger is worth tracing before you file: check each remittance against its period, the employer shares on lines 27 and 19, and that every slip matches your payroll records.
The employer EI figure
Line 19 isn't copied from the slips. The CRA says to multiply the employees' total premiums by the employer's premium rate and report your share. The same applies to lines 27 and 27A: they're your contributions, not totals of a box on the employees' slips.
When and how to file
| Situation | Due date |
|---|---|
| Normal year | The last day of February after the calendar year |
| Your business stops operating | 30 days from the date it stops |
| A partner or the sole proprietor dies | 90 days from the date of death |
| An employee leaves | No change to the due date |
A return counts as on time if the CRA receives it, or it's postmarked, by the due date; if that falls on a weekend or public holiday, the next business day works. For returns filed on or after January 1, 2024, you must file electronically if you have more than 5 slips of the same type for the year. Web Forms is one of the CRA's electronic options.
If you file late
Each slip counts as an information return, and the penalty is based on how many are late. For T4 returns the CRA applies an administrative policy for small filers, as of October 2026:
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| Slips filed late | Penalty |
|---|---|
| 1 to 5 | $100 flat |
| 6 to 10 | $5 a day, up to $500 |
| 11 to 50 | $10 a day, up to $1,000 |
Larger filers pay more per day. The full rules, and the separate penalty for filing on paper when you should have filed electronically, sit with the T4 slip itself.
My verdict
Treat the T4 Summary as a reconciliation, not a form. Before February, total your slips per payroll account, compare line 80 with the year's remittances on your PD7A, and fix any gap above $2 while you still can. Check the account number against your business number and its RP suffix, because one summary goes with each payroll account.
Frequently asked questions
What is a T4 Summary?
It's form T4SUM, the total of all the T4 slips you issued from one payroll account for a calendar year, including employment income, CPP, EI and income tax deducted.
When is the T4 Summary due?
By the last day of February after the calendar year. If your business stops operating, it's due 30 days after that date.
Do I need a T4 Summary for each payroll account?
Yes. The CRA says to fill out a separate T4 Summary for each payroll account.
What if line 80 and line 82 don't match?
Subtract line 82 from line 80. A negative result is an overpayment for line 84; a positive result is a balance due for line 86. The CRA generally ignores a difference of $2 or less.
Must the T4 Summary be filed electronically?
Yes if you have more than 5 slips of the same type for the year, for returns filed on or after January 1, 2024.
