ON Individual Return

Section 1 -- Quick Reference

Quick Reference

Field	Value
Country	Canada -- Ontario
Tax	Provincial income tax (ON428) + Ontario Health Premium + Ontario surtax
Currency	CAD only
Tax year	Calendar year
Primary legislation	Taxation Act, 2007, S.O. 2007, c. 11, Sch. A
Tax authority	CRA on behalf of Ontario
Filing portal	CRA My Account / NETFILE / EFILE
Form	ON428 -- Ontario Tax; ON479 (Credits); ON-BEN (Trillium)
Filing deadline	June 15 (self-employed); payment due April 30
Contributor	Open Accountants Community
Validated by	Live status: https://openaccountants.com/skills/on-individual-return
Skill version	2.0

Ontario Tax Rates (2025)

Ontario Tax Rates (2025)

Taxable Income (CAD)	Rate	Cumulative Tax
0 -- 52,886	5.05%	2,671
52,887 -- 105,775	9.15%	7,510
105,776 -- 150,000	11.16%	12,447
150,001 -- 220,000	12.16%	20,959
220,001+	13.16%	20,959+

Ontario Surtax

• Ontario Surtax — 20% on basic tax exceeding $5,315 + 36% on basic tax exceeding $6,802. Thresholds NOT indexed.

Ontario Health Premium (OHP)

Ontario Health Premium (OHP)

Taxable Income	OHP
0 -- 20,000	$0
20,001 -- 25,000	6% of excess over $20,000 (max $300)
25,001 -- 36,000	$300
36,001 -- 48,000	Step increases to $600
48,601 -- 72,000	$600
72,601 -- 200,000	$750
200,601+	$900 (maximum)

Conservative Defaults

Conservative Defaults

Ambiguity	Default
Unknown province	Do not apply this skill
Unknown bracket year	2025 indexed figures

Section 2 -- Required Inputs and Refusal Catalogue

Required Inputs

• Required Inputs — Minimum viable -- province of residence on Dec 31 (must be Ontario), federal taxable income (T1 line 26000), federal net income. Recommended -- marital status, spouse income, children, property tax/rent paid, municipality. Ideal -- complete T1 data, prior ON428, disability certificate.

Refusal Catalogue

• R-ON-1 -- Not Ontario resident — "Province is not Ontario on December 31."
• R-ON-2 -- Corporations/trusts — "Individual sole proprietors only."
• R-ON-3 -- Part-year resident — "Escalate."
• R-ON-4 -- First Nations exemption — "Escalate."

Section 3 -- Transaction Pattern Library

Ontario tax is computed from federal return data. Transaction classification is in ca-fed-t2125.

Section 4 -- Worked Examples

Example 1 -- Low Income

Input: Taxable income $18,000. Single.

Computation:

• Gross Ontario tax: $18,000 x 5.05% = $909.00
• Basic personal credit: $11,865 x 5.05% = $599.18
• Basic tax: $309.82. Surtax: $0. OHP: $0.
• Ontario tax: $309.82

Example 2 -- Mid-Range

Input: Taxable income $75,000. Single.

Computation:

• $52,886 at 5.05% + $22,114 at 9.15% = $4,694.17
• Credit: $599.18. Basic tax: $4,094.99. Surtax: $0. OHP: $750.
• Ontario tax: $4,844.99

Example 3 -- High Income, Surtax

Input: Taxable income $200,000. Single.

Computation:

• Gross tax through brackets: $18,525.59
• Credit: $599.18. Basic tax: $17,926.41
• Surtax 1: 20% x ($17,926.41 - $5,315) = $2,522.28
• Surtax 2: 36% x ($17,926.41 - $6,802) = $4,004.79
• OHP: $750
• Ontario tax: $17,926.41 + $6,527.07 + $750 = $25,203.48

Section 5 -- Tier 1 Rules (When Data Is Clear)

5.1 Ontario Tax Computation

• Ontario Tax Computation — Taxable income -> 5 brackets -> gross tax -> minus non-refundable credits at 5.05% -> basic tax -> plus surtax -> plus OHP.

5.2 Ontario Surtax

• Ontario Surtax formula — Surtax = 20% x max(0, basic_tax - $5,315) + 36% x max(0, basic_tax - $6,802). Thresholds frozen (not indexed).

5.3 OHP

• OHP basis — Based on taxable income (not net income). Maximum $900. NOT reduced by credits.

5.4 Credits at 5.05%

• Basic personal credit — $11,865 CAD
• Spousal credit — $11,865 minus partner income CAD
• Age (65+) credit — $5,590 CAD

Section 6 -- Tier 2 Catalogue (Reviewer Judgement Required)

6.1 Ontario Trillium Benefit

• Ontario Trillium Benefit — OEPTC: max $1,194 (non-senior). OSTC: $360/person. NOEC: $180 (Northern Ontario only). All reduced by income. Paid by CRA. Flag for reviewer.

6.2 CARE Credit

• CARE Credit — Refundable childcare credit, percentage depends on family income. Flag if client has childcare expenses.

6.3 Multiple Provinces

• Multiple Provinces — If multi-province allocation required (T2203), flag for reviewer.

Section 7 -- Excel Working Paper Template

ONTARIO PROVINCIAL TAX -- Working Paper (2025)

A. INCOME A1. Taxable income (T1 line 26000) ___________

B. ONTARIO TAX B1. Gross Ontario tax (5 brackets) ___________ B2. Ontario non-refundable credits (x 5.05%) ___________ B3. Ontario basic tax (B1 - B2, min 0) ___________ B4. Ontario surtax ___________ B5. Ontario tax before OHP (B3 + B4) ___________ B6. Ontario Health Premium ___________ B7. Ontario tax payable (B5 + B6) ___________

REVIEWER FLAGS: [ ] Province confirmed as Ontario? [ ] Surtax computed on basic tax (after credits)? [ ] OHP NOT reduced by credits? [ ] 2025 indexed thresholds used?

Section 8 -- Bank Statement Reading Guide

Ontario tax is not computed from bank statements directly. See ca-fed-t2125.

Section 9 -- Onboarding Fallback

ONBOARDING QUESTIONS -- ONTARIO PROVINCIAL TAX

1. Province of residence on December 31?
2. Federal taxable income?
3. Federal net income?
4. Marital status and spouse income?
5. Number of children?
6. Property tax or rent paid?
7. Northern Ontario resident?
8. Medical expenses, charitable donations?
9. Disability status?
10. Childcare expenses?

Section 10 -- Reference Material

Reference Material

Topic	Reference
Ontario brackets	Taxation Act, 2007, s. 3
Surtax	Taxation Act, 2007, s. 3(2)
OHP	Taxation Act, 2007, s. 3(5)
Non-refundable credits	Taxation Act, 2007, s. 8+
OTB / OEPTC	Taxation Act, 2007, Part IV
Dividend tax credits	Taxation Act, 2007, s. 19

PROHIBITIONS

• NEVER apply this skill if province is not Ontario on December 31
• NEVER reduce the OHP by tax credits
• NEVER forget the surtax -- it dramatically increases effective rates
• NEVER compute tax for corporations, partnerships, or trusts
• NEVER use prior-year bracket amounts
• NEVER combine with another provincial skill
• NEVER present calculations as definitive

Disclaimer

This skill and its outputs are provided for informational and computational purposes only and do not constitute tax, legal, or financial advice. Open Accountants and its contributors accept no liability for any errors, omissions, or outcomes arising from the use of this skill. All outputs must be reviewed and signed off by a qualified professional before filing or acting upon.

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