Guide to T4A(OAS) Old Age Security Slip

If you or a family member receives Old Age Security (OAS) pension payments in Canada, you'll receive a T4A(OAS) tax information slip each year. This slip is essential for filing your annual income tax return with the Canada Revenue Agency (CRA). For newcomers to Canada — especially those sponsoring parents or grandparents — understanding this slip is important for proper tax planning and compliance.

This guide explains what the T4A(OAS) slip is, what each box means, how it relates to the OAS clawback, and how to report it on your tax return.

What Is Old Age Security (OAS)?

The Old Age Security program is one of Canada's largest pension programs. Unlike the Canada Pension Plan (CPP), OAS is not based on your work history or contributions — it's funded from general tax revenues and is available to most Canadians aged 65 and older who meet residency requirements.

See also: CPP and OAS Retirement Benefits Guide

The OAS program includes several benefits:

• OAS pension: A monthly payment available to most people aged 65 and older who have lived in Canada for at least 10 years after turning 18.
• Guaranteed Income Supplement (GIS): Additional money for low-income OAS pensioners.
• Allowance: Benefits for the spouse or common-law partner of a GIS recipient, or for a survivor, aged 60 to 64.

For newcomers, it's important to know that you generally need at least 10 years of Canadian residence after age 18 to qualify for OAS. If you lived in a country that has a social security agreement with Canada, those years may count toward the residency requirement. Visit canada.ca/old-age-security for eligibility details.

What Is the T4A(OAS) Slip?

The T4A(OAS) — Statement of Old Age Security — is a tax information slip issued by Service Canada each year to everyone who received OAS payments during the previous calendar year. It reports the total OAS payments you received, any income tax deducted, and any OAS recovery tax (clawback) that was applied.

You should receive your T4A(OAS) slip by the end of February for the previous tax year. For the 2025 tax year, for example, you should receive it by the end of February 2026. If you've registered for My Service Canada Account, you can also access your T4A(OAS) slip online at canada.ca/my-service-canada-account.

Understanding Each Box on the T4A(OAS) Slip

The T4A(OAS) slip contains several numbered boxes. Here's what each one means:

Box 18 — Old Age Security Pension

This shows the total gross OAS pension payments you received during the year, before any deductions. This amount is taxable income and must be reported on your tax return at line 11300.

Box 19 — Net Supplements Paid

This shows the total of any Guaranteed Income Supplement (GIS), Allowance, or Allowance for the Survivor payments you received. While these amounts must be reported on your tax return (at line 14600), they are generally not taxable — you'll claim a deduction for the same amount on line 25000, effectively reducing your taxable income by this amount.

Box 22 — Income Tax Deducted

This shows the total income tax that was deducted from your OAS payments during the year. This is a credit against your total tax owing when you file your return. You'll report this amount on line 43700 of your return.

Box 20 — Taxable Part of Net Federal Supplements

In some cases, a portion of the supplements in Box 19 may be taxable. This box shows the taxable portion, if any. This primarily applies in specific situations involving non-residents or partial-year residents.

The OAS Clawback (Recovery Tax)

One of the most important things to understand about OAS is the OAS recovery tax, commonly known as the clawback. If your net income exceeds a certain threshold, you must repay some or all of your OAS pension. For the 2025 tax year, the threshold was approximately $90,997 (this amount is indexed to inflation and increases each year).

Here's how it works:

• If your net income is below the threshold, you keep your full OAS pension.
• If your net income exceeds the threshold, you must repay 15 cents for every dollar of income above the threshold.
• If your net income is high enough (approximately $148,000+ for 2025), your entire OAS pension is clawed back.

The clawback is calculated on your income tax return (using the form T1 — see line 23500 for the social benefits repayment). If you owe a clawback, Service Canada will also adjust your monthly OAS payments for the following year based on your previous year's return.

How to Report T4A(OAS) on Your Tax Return

Follow these steps to properly report your T4A(OAS) information when filing your income tax return:

1. Line 11300 — Old Age Security pension: Enter the amount from Box 18 of your T4A(OAS) slip.
2. Line 14600 — Net federal supplements: Enter the amount from Box 19. This reports GIS and Allowance payments.
3. Line 25000 — Other deductions: If you reported an amount on line 14600, you can generally claim a deduction for the same amount here, making those supplements non-taxable.
4. Line 23500 — Social benefits repayment: If your income triggers the OAS clawback, the amount will be calculated here.
5. Line 43700 — Total income tax deducted: Include the amount from Box 22 with your other tax deductions to claim credit for taxes already paid.

Common Situations for Newcomers

Sponsored Parents and Grandparents

If you've sponsored your parents or grandparents to come to Canada, they may eventually qualify for OAS after meeting the residency requirements. As a sponsor, you should help them understand their tax obligations, including reporting OAS income. Even if their income is low enough that no tax is owing, they should still file a tax return to maintain eligibility for GIS and other benefits.

See also: First-Year Tax Filing Guide

International Social Security Agreements

Canada has social security agreements with many countries. If your parent lived in a country with such an agreement, their years of residence in that country may count toward the 10-year requirement for OAS. They may also receive a pension from that country, which would be reported separately on their Canadian tax return. A list of countries with agreements is available at canada.ca/cpp-international.

Partial OAS Pension

If you lived in Canada for less than 40 years after age 18, you may receive a partial OAS pension. The pension is calculated as 1/40th of the full pension for each complete year of Canadian residence after age 18. For example, if you lived in Canada for 20 years after age 18, you'd receive 20/40 = 50% of the full pension amount.

Non-Residents

If you leave Canada and become a non-resident, your OAS pension may be subject to a 25% non-resident withholding tax (or a lower rate under a tax treaty). This would be reflected on your T4A(OAS) slip. You'd need to file a Canadian tax return to report this income and claim any applicable treaty benefits.

Accessing Your T4A(OAS) Slip

There are several ways to get your T4A(OAS) slip:

• By mail: Service Canada mails the slip to your address on file by the end of February.
• My Service Canada Account: View and print your slip online at My Service Canada Account.
• CRA My Account: Your T4A(OAS) information is also available in your CRA My Account once it's been processed.
• By phone: Call Service Canada at 1-800-277-9914 to request a copy.

Tips for Tax Season

• File your return even if no tax is owing: Filing ensures you maintain eligibility for GIS and other income-tested benefits.
• Use NETFILE-certified software: Free tax software like Wealthsimple Tax or GenuTax can automatically populate your return with T4A(OAS) information if you use CRA's Auto-fill feature.
• File on time: The deadline for most individuals is April 30. Late filing can affect your GIS payments.
• Consider income splitting: If one spouse receives OAS and the other doesn't, look into pension income splitting options to reduce the overall tax burden and potentially avoid the OAS clawback.
• Get free tax help: The CRA's Community Volunteer Income Tax Program (CVITP) offers free tax clinics for people with modest incomes, including seniors.

Understanding your T4A(OAS) slip is an important part of managing your finances as a senior in Canada. By knowing what each box means and how to report the information on your tax return, you can ensure you're meeting your tax obligations while maximizing the benefits available to you.

See also: CRA My Account Setup Guide