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Why Is My Paycheque Different This Week? Every Reason Your Pay Changes

Updated

Your paycheque amount changes regularly throughout the year for reasons that are often predictable once you know what to look for.

Common causes at a glance

CausePaycheque impactWhen it happens
CPP annual ceiling reachedHigher (CPP stops being deducted)Sept–Dec depending on income
EI annual ceiling reachedHigher (EI stops being deducted)Oct–Dec depending on income
CPP2 starts in JanuaryLower (additional deduction if income >~$71K)January each year
New benefit enrollment (dental/health/LTD)Lower (premium deductions start)After open enrollment or start date
Raise effective dateHigherDate raise takes effect
Retroactive raise payHigher (one-time larger amount)When HR processes the retroactive period
TD1 change (fewer credits claimed)Lower (more tax withheld)After filing new TD1
Group RRSP / pension enrollmentLower (savings deductions start)After enrollment period
Garnishment or CRA Requirement to PayLower (withheld for creditor/CRA)Immediately upon legal order
Day count differs (bi-weekly timing)Lower/higherSome months have 3 paydays

CPP and EI ceilings 2025

Once you hit the annual ceiling, your employer stops deducting that premium for the rest of the year — and your take-home pay rises by the corresponding amount:

Deduction2025 annual maximumEmployee rateApprox. months (at $70K salary)
CPP (employee)$3,867.505.95% of insurable earningsJan–Oct
CPP2 (employee)up to ~$3964.0% on earnings $71,300–$81,900Limited months if income >$71K
EI premium$1,049.121.66% of insurable earningsJan–Nov

Why your paycheque goes up in the fall: if you earn $70,000/year, your CPP ceiling is hit around October and EI around November. In those final months you take home approximately $150–$250 more per pay period. Both deductions restart January 1 at the new year’s rates.


TD1 and withholding adjustments

Your TD1 tells your employer what personal tax credits you are claiming. Common TD1 credit codes:

TD1 LineCredit2025 federal value
Basic personal amountEveryone$16,129
Age amount65+$8,790
Spouse/common-law partnerIf applicableUp to $16,129
Eligible dependantSingle parent with childUp to $16,129
Disability amountDTC certificate$9,872
Caregiver amountSupporting dependentVaries

Filing a new TD1 at any time asks your employer to recalculate withholding. This takes effect on the next pay period after filing. If you have a major life change (marriage, divorce, new dependent, DTC approval), update your TD1 to ensure accurate withholding.


Retroactive pay: why one paycheque looks huge

When a salary increase is applied backward to earlier pay periods, your employer calculates the arrears and pays them all at once. This retroactive amount is combined with your regular pay for that period:

  • Tax impact: the combined amount is taxed as if it were all regular income for that pay period, which inflates the withholding. You will not actually owe more tax for the year — the excess is returned as a refund at tax time.
  • CPP/EI impact: retroactive pay is subject to CPP and EI if you have not yet hit the annual ceiling.
  • You cannot control this: Canadian payroll rules require withholding at the time of payment, not at the time it was earned.

Example: a $6,000 retroactive raise paid in one lump sum with a $3,000 regular paycheque = $9,000 grossed up for withholding in that period. Federal and provincial tax is withheld at the rate for a $9,000 semi-monthly paycheque (annualized to $108,000), far above your actual annual income. Expect a refund at tax time.


Understanding garnishments and CRA Requirement to Pay

A wage garnishment directs your employer to withhold a portion of each paycheque and send it to a creditor or CRA:

TypeAuthorityAmount withheld
Court judgment garnishmentCourt orderUp to 20% of net wages (varies by province)
CRA Requirement to PayCRA — no court neededUp to full amount owed; employer must comply immediately
Family law support (FRO)Family Responsibility OfficeArrears and ongoing support amounts

If a garnishment appears on your paycheque without notice:

  1. Check your mail for a prior notice (court judgment or CRA letter)
  2. Contact CRA at 1-888-863-8657 or the creditor directly
  3. Arrange repayment to potentially lift the garnishment

When benefit deductions change

Common scenarios where new payroll deductions appear mid-year:

SituationNew deduction
Joined employer health/dental planEmployee premium (typically $40–$200/month)
Enrolled in group RRSPYour chosen % of salary
Pension plan vesting period completeRPP employee contribution (1–9% of salary)
Short-term disability (STD) plan enrolledSmall premium (varies by insurer)
Life insurance increasedHigher premium

If you do not recognize a deduction, ask payroll for a detailed breakdown — they are required to provide one. Every deduction must be authorized in your employment agreement or separately consented to.


For a paycheque breakdown you do not understand

  1. Ask payroll for a detailed pay stub explanation — if your pay stub is unclear, your employer must explain each line
  2. Identify gross pay, CPP, CPP2, EI, income tax (federal + provincial), benefits, RRSP, and any other deductions
  3. Check your TD1 form on file — ask payroll what credits they have recorded
  4. Review your benefit enrollment confirmation if deductions changed recently
  5. If you believe there is an error, contact payroll immediately — most payroll errors are corrected on the next run