Every rate, bracket, threshold and deadline on this site comes from one rules file. Each number in that file points to one of the pages below, almost all of them published by the Canada Revenue Agency or the Department of Finance.
Where our numbers come from
Rules file: 2026 tax year, version 2026.3, last checked October 4, 2026.
- CRA T4127 Payroll Deductions Formulas, 122nd edition, effective January 1, 2026
- CRA T4127 Payroll Deductions Formulas, 123rd edition, effective July 1, 2026 (BC, NL, PE mid-year changes)
- CRA: Tax rates and income brackets to be used on the 2026 tax return
- EY tax alert: Manitoba Budget 2026 (brackets not indexed)
- CRA: When to register for and start charging the GST/HST
- CRA: GST/HST calculator (and rates)
- CRA: MP, DB, RRSP, DPSP, ALDA, TFSA limits, YMPE and the YAMPE
- CRA: Who has to pay required tax instalments
- CRA P148: Resolving your dispute, objection rights under the Income Tax Act
- CRA Income Tax Folio S1-F3-C2, Principal Residence
- CRA T4036 Rental Income guide (recapture and terminal loss)
- CRA: Completing Schedule 3 (capital gains)
- CRA RC4058 Quick Method of Accounting for GST/HST (Rev. 25)
- CRA RC4022 General Information for GST/HST Registrants
- CRA Form T2091(IND) Designation of a Property as a Principal Residence by an Individual (2025)
- CRA Form T776 Statement of Real Estate Rentals (2025): lines 9947 recapture, 9948 terminal loss
- CRA, Completing the T5 slip (gross-up and dividend tax credit)
- Ontario, Ontario dividend tax credit
- CRA, Corporation tax rates
- PwC, 2026 Ontario budget tax highlights (small business rate 2.2% from July 1, 2026)
- KPMG, Highlights of the 2026 Newfoundland and Labrador budget
- TaxTips.ca, Dividend tax credit for non-eligible dividends (provincial rates)
- CRA, Prescribed interest rates, October to December 2026
- Service Canada, OAS recovery tax and payment amounts
- Service Canada, CPP payment amounts
- TaxTips.ca, 2026 non-refundable tax credit amounts (provincial age and pension amounts)
- CRA, IC78-18R7 Registered Retirement Income Funds (prescribed factors)
- CRA, Guide T4040, RRSPs and other registered plans for retirement
- CRA, Canada workers benefit: how much you can get
- CRA, Completing Schedule 3 (capital gains)
- Ontario, Estate administration tax
How we keep them current
We recheck the sources at the start of each tax year, whenever a federal or provincial budget changes a rate, and whenever CRA publishes a new payroll formula. The date on the rules file shows the last full check. When a rule changes part way through a year, as happened in BC, Newfoundland and Labrador and PEI in 2026, we use the value that applies to the whole year on your return, and say so.
See how our answers work for how the rules, the math and the AI are kept apart. Spotted something out of date? Tell us.