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Why tax refunds happen

See how the tax taken off your pay, instalments and credits compare with your final tax bill to give a refund or a balance owing.

Published by Beaver Ledger · Edited

How refunds work on a Canadian personal return. The examples assume nothing else changes; they aren't tied to an income or tax year.

The question

Why do I get a refund even though tax came off each paycheque?

You get a refund when the tax already taken off your pay, plus any refundable credits, is more than your final tax for the year. Payroll deductions are payments toward that final bill, and they rarely match it exactly.

  1. 01Payroll deductions are an estimate
  2. 02Example: one tax bill, two outcomes
  3. 03How a donation can change the result
  4. 04If a result surprises you

Payroll deductions are an estimate

Your employer takes off income tax as you're paid. Your return then works out your actual tax for the whole year. Having two jobs, changing hours, or claims your payroll didn't know about can all leave a gap. A refund doesn't mean anyone made a mistake.

Sources: CRA: T4 slip guide (opens in a new tab); CRA: Federal income tax and benefit information for 2025 (opens in a new tab)

Example: one tax bill, two outcomes

Say your final tax is $9,000, you have no refundable credits, and $10,000 was taken off your pay. You get $1,000 back. If only $8,000 had been taken off, you would owe $1,000 instead.

Both people paid the same $9,000 of tax for the year. A bigger refund only means more was taken off earlier, so it doesn't tell you how much tax you paid.

How a donation can change the result

An eligible donation credit lowers your tax. If what was taken off your pay stays the same, that means a bigger refund or a smaller balance owing. If your tax is already zero, the credit has nothing left to reduce, so a gift doesn't always change your refund.

Sources: CRA: Gifts and Income Tax 2025 (opens in a new tab)

If a result surprises you

Compare the tax taken off your pay with this year's return, not with last year's refund. The calculator asks for the tax deducted on your T4s because it can't guess what was taken off your pay.

  • Add up box 22 on every T4.
  • Check for income you left out and claims that changed.
  • Read your notice of assessment for any changes the CRA made.
  • Use full filing software or get help if you pay instalments, run a business or have complex credits.
Sources: CRA: Federal income tax and benefit information for 2025 (opens in a new tab)

Sources checked for this editorial revision on October 3, 2026. Educational content from Beaver Ledger; no professional review is claimed. Methods and limitations · Editorial practices and corrections.