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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

Cause Paycheque impact When it happens
CPP annual ceiling reached Higher (CPP stops being deducted) Sept–Dec depending on income
EI annual ceiling reached Higher (EI stops being deducted) Oct–Dec depending on income
CPP2 starts in January Lower (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 date Higher Date raise takes effect
Retroactive raise pay Higher (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 enrollment Lower (savings deductions start) After enrollment period
Garnishment or CRA Requirement to Pay Lower (withheld for creditor/CRA) Immediately upon legal order
Day count differs (bi-weekly timing) Lower/higher Some 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:

Deduction 2025 annual maximum Employee rate Approx. months (at $70K salary)
CPP (employee) $3,867.50 5.95% of insurable earnings Jan–Oct
CPP2 (employee) up to ~$396 4.0% on earnings $71,300–$81,900 Limited months if income >$71K
EI premium $1,049.12 1.66% of insurable earnings Jan–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 Line Credit 2025 federal value
Basic personal amount Everyone $16,129
Age amount 65+ $8,790
Spouse/common-law partner If applicable Up to $16,129
Eligible dependant Single parent with child Up to $16,129
Disability amount DTC certificate $9,872
Caregiver amount Supporting dependent Varies

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:

Type Authority Amount withheld
Court judgment garnishment Court order Up to 20% of net wages (varies by province)
CRA Requirement to Pay CRA — no court needed Up to full amount owed; employer must comply immediately
Family law support (FRO) Family Responsibility Office Arrears 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:

Situation New deduction
Joined employer health/dental plan Employee premium (typically $40–$200/month)
Enrolled in group RRSP Your chosen % of salary
Pension plan vesting period complete RPP employee contribution (1–9% of salary)
Short-term disability (STD) plan enrolled Small premium (varies by insurer)
Life insurance increased Higher 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