Why province matters
The planner estimates federal tax and the selected province or territory's tax rules as part of each retirement year. That can affect RRSP/RRIF withdrawal timing, pension-income splitting, OAS recovery tax interactions and the optimizer's preferred household strategy.
Quebec note: if your pension contribution history is primarily QPP rather than CPP, use your official Retraite Québec pension estimate as the calculator input.
Future tax thresholds are projections because future legislation is unknown. Recalculate after tax-law changes and verify material implementation decisions.