If you live in Ontario, your provincial taxes are filed as part of your federal return using three Ontario-specific forms: Form ON428 calculates the provincial tax you owe, Form ON479 claims Ontario’s refundable credits, and Form ON-BEN applies for the Ontario Trillium Benefit and the Senior Homeowners’ Property Tax Grant. All three are submitted together with your federal return to the Canada Revenue Agency, which collects Ontario’s personal income tax on the province’s behalf under a tax collection agreement. You never send anything directly to the Ontario government.
Form ON428: Ontario Tax
ON428 is the main provincial tax form and the one every Ontario resident completes. It applies Ontario’s five progressive tax brackets to your taxable income, subtracts non-refundable credits, and produces the provincial tax figure that gets added to your federal tax.1Canada Revenue Agency. Ontario Tax Information for 2025 You fill it out after completing the first five steps of your federal return, because ON428 pulls figures from the federal calculation.
Two extra charges are built into this form and often catch people by surprise. The first is the Ontario surtax, which is levied on top of your provincial tax once that tax passes certain thresholds; the higher-tier portion effectively stacks to 56%. The second is the Ontario Health Premium, which scales from $0 for taxable income of $20,000 or less up to a maximum of $900 for income above $200,000.2Canada Revenue Agency. Payroll Deductions Tables – CPP, EI, and Income Tax For most employed Ontarians, part of the health premium is already deducted through payroll.
The non-refundable credits handled on ON428 include the Ontario basic personal amount, the age amount, the spouse or common-law partner amount, the disability amount, tuition fees, medical expenses, and charitable donations. Ontario also offers the Low-Income Individuals and Families Tax (LIFT) Credit and the Ontario tax reduction, either of which can bring your provincial tax to zero if you qualify.
Form ON479: Ontario Credits
ON479 is where you claim Ontario’s refundable tax credits. The distinction matters: non-refundable credits on ON428 can only reduce tax you already owe, while refundable credits on ON479 can produce a payment even if your tax bill is zero.3Government of Ontario. Filing Your Personal Income Tax Return If your income is low or you already owe nothing, ON479 is the form that can actually put money in your pocket.
Three credits sit on this form. The Ontario Childcare Access and Relief from Expenses (CARE) credit is calculated from your family income and the eligible childcare expenses you claimed on your federal return. The Ontario Seniors Care at Home Tax Credit is available to individuals or couples where at least one person is 70 or older by December 31, with combined family net income under $65,000.1Canada Revenue Agency. Ontario Tax Information for 2025 The seniors’ public transit credit is for residents 65 and older with eligible transit expenses. Skip ON479 when one of these applies and you leave money behind.
Form ON-BEN: Trillium Benefit and Senior Homeowners’ Property Tax Grant
ON-BEN is your application for the Ontario Trillium Benefit, which bundles three programs into a single monthly payment: the Ontario Energy and Property Tax Credit, the Northern Ontario Energy Credit, and the Ontario Sales Tax Credit.4Canada Revenue Agency. Province of Ontario The same form covers the Ontario Senior Homeowners’ Property Tax Grant.
You report your rent or property tax paid during the year directly on ON-BEN, and Northern Ontario residents enter their home energy costs here. Seniors claiming the property tax grant enter their property tax on line 61120.5Government of Ontario. Senior Homeowners Property Tax Grant The CRA calculates your entitlement based on your income and housing costs. Trillium payments based on your 2025 return begin in July 2026 and are issued monthly on the 10th (or the nearest business day) through June 2027.4Canada Revenue Agency. Province of Ontario
Which Forms Apply to You
Your province of residence on December 31 determines which provincial forms you complete. If you lived in Ontario on that date, Ontario’s forms cover the entire year’s income regardless of where you earned it.6Canada Revenue Agency. Income Tax Folio S5-F1-C1 – Determining an Individuals Residence Status
Every Ontario resident completes ON428. You add ON479 only if one of its three credits applies to your household. You add ON-BEN if you paid rent, property tax, or (in Northern Ontario) home energy costs during the year, or if you’re a senior homeowner applying for the property tax grant. Most filers end up with two or all three.
Documents to Gather Before You Start
Before opening the forms, pull together:
- T4 slips from employers, along with any T4A slips for pensions or commissions and T5 slips for investment income. T4s are issued by the end of February.
- Rent receipts or property tax bills for the full year, needed for ON-BEN.
- Home energy costs, if you live in Northern Ontario and want the Northern Ontario Energy Credit.
- Social insurance numbers and net income figures for any dependents you’re claiming credits for.
- Your spouse or common-law partner’s income, which affects family-based credits and the Trillium Benefit calculation.
- Childcare receipts, if you’re claiming the CARE credit on ON479.
If you use CRA My Account, many of these slips are available digitally. The Auto-fill My Return feature in NETFILE-certified software can pull T4, T5, T3, T2202, RC62, RC210, and RRSP slips directly from the CRA, though you’re still responsible for verifying accuracy.7Canada Revenue Agency. Auto-fill My Return for Professional Tax Preparers T3 and T5013 slips sometimes aren’t issued until the end of March, so if you have trust or partnership income, you may need to wait before filing.8Canada Revenue Agency. Get a Copy of Your Slips
How to Complete and File the Forms
Most Ontario residents file with NETFILE-certified tax software, which handles all three provincial forms automatically. Once you enter your income slips, residency, and housing costs, the software populates ON428, ON479, and ON-BEN from your inputs and transmits everything to the CRA electronically. The CRA maintains a list of certified options, including several free ones.
On paper, download the PDFs from the CRA website. Physical copies are sometimes available at post offices and Service Canada centres during tax season. You complete your federal return first, then use your taxable income figure to work through ON428’s bracket calculations. The form walks through each bracket, applies non-refundable credits, adds the surtax if applicable, and calculates the health premium. ON479 and ON-BEN follow, using income and housing cost figures from your return and receipts.
Whichever route you take, the three provincial forms travel with your federal return as a single package to the CRA.
Filing Deadline and Late Penalties
The deadline for your 2025 return is April 30, 2026.9Canada Revenue Agency. Get Ready to File a Tax Return Self-employed filers and their spouses have until June 15 to file, but any balance owing is still due April 30.
If you owe a balance and file late, the penalty is 5% of the unpaid amount plus 1% for each full month the return is outstanding, up to 12 months.10Canada Revenue Agency. Interest and Penalties on Late Taxes That can reach 17% on top of the tax itself, alongside daily compound interest. Even if you can’t pay right away, filing on time avoids the late-filing penalty. The CRA will arrange a payment plan, which costs far less than the penalty stack.
Late filing also delays Ontario Trillium Benefit payments, because the CRA can’t calculate your entitlement without a completed return and a completed ON-BEN.