Line 43700 on your Canadian T1 return is where you report the total income tax deducted at source during the year. You get the figure by adding together the income-tax-deducted amount from every Canadian information slip you received, including your T4s, pension slips, and RRSP or RRIF withdrawal slips. That total is credited against your tax bill, so it either shrinks what you owe or grows your refund.1Canada Revenue Agency. Line 43700 – Total Income Tax Deducted
Which Slips and Boxes Feed the Line
Different slips use different box numbers for tax withheld. Pull the correct box from each:1Canada Revenue Agency. Line 43700 – Total Income Tax Deducted
Box 22 on:
- T4 (employment income)
- T4A (pension, retirement, annuity, and other income)
- T4A(OAS) (Old Age Security)
- T4A(P) (Canada Pension Plan benefits)
- T4A-RCA (distributions from a Retirement Compensation Arrangement)
- T4E (Employment Insurance and other benefits)
Box 28 on the T4RIF (Registered Retirement Income Fund income).
Box 30 on the T4FHSA (First Home Savings Account) and T4RSP (RRSP income).
Most slips arrive by the end of February. If one is missing, you can usually find a copy in your CRA My Account once the issuer has filed it.2Canada Revenue Agency. Get a Copy of Your Tax Slips
Adding the Numbers, and What Not to Include
The calculation is straightforward. Add every income-tax-deducted amount from every slip and enter the total on Line 43700 of your T1. If you had two employers and collected Old Age Security, that means Box 22 from both T4s plus Box 22 from your T4A(OAS).
Only income tax belongs here. Leave out CPP contributions (T4 Box 16), EI premiums (Box 18), and registered pension plan contributions (Box 20). Those numbers look similar but are reported on other lines. Including them inflates your withholdings and creates a discrepancy the CRA will catch.
Quebec Residents: Exclude the Provincial Tax
If you lived in Quebec on December 31, your slips may show both federal and Quebec provincial tax withheld. Only the federal portion goes on Line 43700. The Quebec provincial tax belongs on your separate Revenu Québec return.1Canada Revenue Agency. Line 43700 – Total Income Tax Deducted Mixing the two is one of the more common Quebec filing errors and leads to a reassessment.
If you lived outside Quebec but had Quebec provincial tax withheld from some income, the CRA says to include those amounts on Line 43700 of your federal return.
If a Slip Is Missing or Arrives Late
The CRA does not want you to skip income or withholdings because a slip is missing. Estimate the amount from your pay stubs or bank statements and report the estimate.2Canada Revenue Agency. Get a Copy of Your Tax Slips
Include a note with your return giving the payer’s name and address, the type of income, and the steps you’re taking to obtain the official slip. Paper filers should attach the supporting pay stubs or statements; electronic filers should keep them on hand. When the real slip eventually arrives and the numbers differ, request an adjustment.
Pension Income Splitting Changes Both Spouses’ Line 43700
Couples electing to split eligible pension income on Form T1032 must move a proportionate share of the tax withheld along with the income. If one spouse transfers 50% of their eligible pension to the other, 50% of the tax withheld on that pension also shifts to the receiving spouse’s Line 43700.3Canada Revenue Agency. How to Calculate Income Tax Deducted at Source Entered on Line 43700 of Your Return
When a single slip covers both eligible and non-eligible pension income, you have to isolate the tax that relates to the eligible portion. Divide the eligible pension amount by the total pension amount on the slip, then multiply by the total tax withheld. Step 5 of Form T1032 walks through the calculation.
Instalment Payments Go on a Different Line
Quarterly instalment payments, the kind required when you earn significant income with no tax withheld (rental, investment, or self-employment), do not belong on Line 43700. They go on Line 47600.4Canada Revenue Agency. Line 47600 – Tax Paid by Instalments Line 43700 tracks what a third party withheld from you; Line 47600 tracks payments you sent directly. Combining them overstates your withholdings and delays processing.
For 2026, instalments are required if your net tax owing exceeds $3,000 in the current year and also exceeded $3,000 in either of the two prior years. Quebec residents face a lower federal threshold of $1,800 because provincial tax is handled separately.5Canada.ca. Required Tax Instalments for Individuals
How the Total Affects Your Refund or Balance
Your Line 43700 total feeds into Line 48200 (total credits), along with Line 47600 and other credits. The CRA subtracts Line 48200 from Line 43500 (total payable). A negative result is a refund, reported on Line 48400.6Canada Revenue Agency. Line 48400 – Refund A positive result is a balance owing. The larger your Line 43700 figure, the more of your tax bill is already paid.
The CRA’s service standard for issuing a Notice of Assessment is 2 weeks for electronic returns and 12 weeks for paper returns.7Canada Revenue Agency. The Level of Service You Can Expect from the CRA This Tax Season
Deadlines, Penalties, and Interest If You Still Owe
For the 2025 tax year, most individuals must file by April 30, 2026. Self-employed filers (or those with a self-employed spouse) have until June 15, 2026 to file, but any balance owing is still due April 30.8Canada.ca. Get Ready to File a Tax Return – Personal Income Tax Extra time to file is not extra time to pay.
Filing late with a balance owing triggers a penalty of 5% of that balance plus 1% for each full month the return remains unfiled, up to 12 months.9Canada Revenue Agency. Interest and Penalties on Late Taxes – Personal Income Tax If the CRA assessed a late-filing penalty in any of the three prior years and issued a formal demand to file, the penalty rises to 10% plus 2% per month for up to 20 months.
Compound daily interest also accrues on any unpaid balance starting May 1. The prescribed rate on overdue taxes for the second quarter of 2026 is 7%.10Canada Revenue Agency. Interest Rates for the Second Calendar Quarter If you know you’ll owe and can’t pay in full, file on time anyway. That avoids the late-filing penalty while you arrange payment.