Methodology & Sources

Source authorities

Federal rules, brackets, and credits come from the Canada Revenue Agency (CRA). Provincial/territorial tax rates come from each province's published schedule.

Update cadence

We review calculators each January for the new tax year and again when CRA publishes mid-year indexation or rule changes. Each calculator page shows its own "Last updated" date from the file's last git commit.

Where the math lives

Calculation logic lives in tested TypeScript files under src/utils/, separated from UI, so every number can be traced back to a tested function.

Handling ambiguous rules

Where CRA guidance is ambiguous or depends on facts we can't observe (residency mid-year, partial-year credits, dependent circumstances), calculators use the most common interpretation and flag assumptions inline.

Not financial advice

CATaxTools provides general information only. It is not tax, legal, or financial advice. For a binding answer, speak to a registered accountant or tax professional.