Mid-year payroll migration: preserve year-to-date evidence

Freeze a clear cutover

Choose the last pay completed in the old system and the first pay to be calculated in the new one. Preserve the old register and do not edit it to make the new system agree.

Bring forward exact evidence

• Gross and taxable earnings through the cutover.
• CPP pensionable earnings/contributions, CPP2 where applicable, EI insurable earnings/premiums and income tax withheld.
• Pay periods completed, vacation balances, current TD1 forms and any CRA authorization letters.
• Source payroll register/export, employee-level totals and a reviewer sign-off.

Reconcile before the first live approval

Compare old-system totals, opening balances and the new-system projection employee by employee and for the company. Differences must be explained and corrected additively; a software change does not change remittance, T4 or recordkeeping duties.