How early can I apply?

You can apply up to 11 months before the month you want your OAS pension to start, and payments can begin no earlier than the month after your 65th birthday.

Should I defer my OAS pension?

You can delay OAS for up to 60 months after 65, and each month of deferral permanently increases the payment. Whether that helps depends on your income and plans; the trade-offs and current rates are explained on canada.ca.

Is the Guaranteed Income Supplement taxable?

No, GIS payments are not taxable, although you must still report them on your income tax return. GIS eligibility is reviewed every year, usually automatically when you file your taxes on time.

What if I have lived outside Canada?

List all periods of residence outside Canada on the form. Canada has social security agreements with many countries that can count foreign periods toward OAS eligibility, and Service Canada applies them when reviewing your file.

Can I get GIS without this form if I already receive OAS?

Yes. If your OAS pension is already in place, you apply for the supplement with Form ISP-3025, the standalone GIS application.

Social Security

Fill Out Form ISP-3550 Online

Application for the Old Age Security Pension and the Guaranteed Income Supplement

Employment and Social Development Canada

Combined paper application for the Old Age Security pension and the Guaranteed Income Supplement.

Reviewed July 2026

How it works

1
Open the form. The official PDF loads straight into the editor, no download needed first.
2
Fill it out in the editor. Click anywhere to type, add checkmarks and place your signature.
3
Download your PDF. Save the completed form, ready to print or submit.

Form ISP-3550 is the combined paper application for the Old Age Security pension and the Guaranteed Income Supplement. Old Age Security is a monthly pension payable to most Canadians aged 65 and over who meet the residence requirements, and the Guaranteed Income Supplement adds a non-taxable monthly amount for lower-income OAS pensioners. The 10-page application ships with its own reference guide, Form ISP-3550A.

You can complete ISP-3550 in the Universal PDF editor. Fill in each section on screen, check your residence history carefully, then download the finished PDF to print, sign, and mail to Service Canada.

What is Form ISP-3550 used for

The form applies for two benefits at once. The Old Age Security pension is based on age and years of residence in Canada rather than work history, so the application focuses on where you have lived since age 18. The Guaranteed Income Supplement is an income-tested addition for OAS pensioners, so the form also collects income information for you and, if applicable, your spouse or common-law partner.

Applying for both together means Service Canada can assess GIS eligibility as soon as your OAS pension is in place, without a second application. Current payment rates and income thresholds are published on canada.ca.

Who applies with Form ISP-3550

You can apply if you are 64 or older, meet the OAS residence requirements, and have not been automatically enrolled. Many people receive a letter from Service Canada saying they will be enrolled automatically the month after they turn 64; if you received that letter and the details are correct, you do not need this form.

People living in Canada generally need at least 10 years of residence after age 18 to qualify, and people living outside Canada generally need at least 20 years. Time in countries that have a social security agreement with Canada may help you qualify. If you are unsure, apply anyway and let Service Canada assess your record.

How to fill out Form ISP-3550

Keep the ISP-3550A reference guide beside you as you work through the application:

Enter your Social Insurance Number, legal name, date of birth, and current address.
List every country you have lived in since age 18 with arrival and departure dates. This residence history drives your OAS entitlement, so be as precise as you can.
Choose when you want your pension to start, including whether you want to defer it past 65 for a higher monthly amount.
Complete the GIS income section, including your marital status and your spouse's or partner's information if you have one.
Provide banking details for direct deposit.
Sign and date the application, and have your spouse or partner sign where required for the GIS portion.

How to submit it

Mail the signed application to the Service Canada office for your province or territory. The addresses are listed on canada.ca, and if you are applying from outside Canada you use the office for the province where you last lived. You can also deliver the form to a Service Canada office in person.

Most applicants can apply online instead through My Service Canada Account. Use one route only; duplicate applications slow processing down.

Frequently asked questions

No. If Service Canada wrote to say you will be enrolled automatically and the information in the letter is correct, no application is needed. Use ISP-3550 only if you were not auto-enrolled or the letter asked you to apply.

Universal PDF is an independent product and is not affiliated with or endorsed by any government agency. Forms are provided from official government sources; always confirm you have the current version before filing.

This form is reproduced from official Canadian government sources. Universal PDF is not affiliated with or endorsed by any Canadian federal or provincial government body; always confirm you have the current version on the official site.