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 at the start of each calendar tax year (1 January), when CRA publishes annual indexation figures each fall (typically November, ahead of the rollover), each quarter for the CRA prescribed interest rate, and on federal or provincial Budget day when changes are announced. Each calculator page shows its own "Last updated" date from the file's last git commit, falling back to the build date where no history is available. In July 2026 we completed a full-site accuracy review — roughly 200 calculator, reference, and article surfaces re-checked against primary CRA and provincial sources. The full policy, including how corrections are handled, is in our editorial policy.

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. The site currently runs 115+ calculators across roughly 480 pages, backed by an automated suite of 1,600+ tests — including anchor tests pinned to published CRA figures (for example, RRIF minimum withdrawal factors under Income Tax Regulation 7308) that fail loudly if a rate is changed accidentally. Rates and thresholds are defined once in central, year-keyed data files, so one verified update flows through every page that uses the figure, and every build checks internal links sitewide before it deploys.

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.