Calculation methodology

Payroll source deductions and annual employment-tax estimates answer different questions. Intagrex keeps the two methods separate rather than applying one simplified formula to both.

Annual employment-tax estimate

The public calculator uses the province or territory of residence and the applicable annual federal, provincial, territorial, or Quebec rates. It estimates employment-income tax and employee CPP/QPP, EI, and QPIP contributions where applicable.

Supported deductions are applied only in the places permitted by the selected calculation strategy. The result identifies the effective rule edition used for the estimate.

Payroll source deductions

Business payroll calculations use province of employment and effective-dated implementations of CRA T4127/T4032 or Revenu Québec TP-1015.F-V methods. These calculations are available only through the authenticated payroll service.

Rule packages and rounding

Each rule package records its official edition, source hash, effective dates, validation report, and reviewed strategy version. Monetary values are returned to the nearest cent using the strategy’s documented rounding points.

If no published rule package exactly covers the requested jurisdiction and year, the calculator reports that an estimate is unavailable rather than substituting another jurisdiction or guessing.

Important limitations

The estimate is not a tax return. It excludes refundable benefits, family and dependant credits, investment income, self-employment income, and other circumstances needed for complete T1 preparation. See the terms and limitations for more detail.