How to Ask Service Canada to Reconsider an OAS or GIS Decision

Which decisions use this process?

Service Canada’s OAS reconsideration page covers the OAS pension, GIS, the Allowance and the Allowance for the Survivor. If your decision letter is about one of these benefits, start with that page. It explains the methods and the later tribunal step in one place.

Check the name of the benefit on your letter. A Canada Pension Plan disability decision or an Employment Insurance decision has a different process. The site’s CPP disability reconsideration guide and EI reconsideration guide are not substitutes for the OAS instructions. The benefit name matters because the deadlines and forms are not interchangeable.

If you are still trying to understand a GIS eligibility or amount explanation, start with the current official GIS information linked from Service Canada’s reconsideration page. It does not replace your decision letter or the reconsideration request.

Count from receipt of the decision letter

Service Canada says you must request reconsideration within 90 days of receiving your decision letter. That is not phrased as 90 days from the date printed on it. Keep the letter and any envelope or delivery record you have, and act promptly. This guide does not calculate a personal deadline from an assumed mailing time.

If the letter is unclear, missing, or the time is close, use Service Canada’s contact route immediately to ask about your specific situation. Do not wait for a website to interpret a deadline for you. Also do not use the 30-day EI reconsideration window for an OAS or GIS decision.

What should you put in the request?

Start with the decision you want reviewed and explain why you disagree. Service Canada’s written-request instructions ask for your name, address, telephone number, Social Insurance Number or Client Identification Number, a detailed explanation, any new information that could affect the decision, and your signature and date. The online or form route will prompt for its required fields.

Useful supporting material depends on the reason Service Canada gave. If the letter says information is missing, identify what you have that addresses it. If you think a recorded fact is wrong, say which fact and provide the record you want reviewed. Do not make up a reason or send sensitive records to Canadian Money Help; submit documents only through an official Service Canada route.

Keep a copy of what you send and a note of how and when you sent it. This is ordinary recordkeeping, not a guarantee that Service Canada will accept the request or change the decision. It helps you describe the submission if you need to follow up.

Choose the submission route

Online: Sign in to My Service Canada Account from the official reconsideration page. Service Canada points to Manage my benefits in the OAS section, then If you disagree with a decision. Follow the current screen instructions and review the information before sending it.

Form: Service Canada provides the Request for Reconsideration of an Old Age Security decision, ISP-3134. Use the form link on its page so you get the current version. Sign and date a paper request. Service Canada says to mail it to the return address on your decision letter or submit it in person at a Service Canada office.

Signed letter: You can also write a request containing the identity, contact, explanation and new-information details Service Canada lists. Sign and date it, then use the same paper delivery routes. Do not send it to CRA: Service Canada administers this process.

These are alternative ways to ask for the same first-stage review. Pick one route you can complete accurately and on time; repeating the request through every channel is not an extra appeal step. If you need help accessing MSCA or preparing a paper submission, ask Service Canada what it accepts.

What happens after you submit it?

Service Canada says someone who did not make the original decision will review the application and any new information. It warns that reconsiderations can take several months, depending on the case. The new decision is sent by mail. Check that Service Canada has your current mailing address and watch for a request for more information.

A reconsideration request does not, by itself, tell you what the final benefit amount will be or when a payment will arrive. If your concern is a missing deposit rather than a decision you disagree with, use the payment or contact instructions for the benefit first. Keep the issues separate when speaking to Service Canada.

For example, someone receives a GIS denial letter and believes a piece of income information is missing. The practical sequence is to note when the letter arrived, read the reason, gather the relevant record, and send a reconsideration request through MSCA or a signed paper route within the 90-day window. Service Canada, not this example, decides whether the information changes the outcome.

If you still disagree with the new decision

After reconsideration, Service Canada points to the Social Security Tribunal of Canada as the next step if you disagree with the new decision. The tribunal is independent of Service Canada. For an OAS or GIS General Division appeal, the tribunal says it must receive your appeal within 90 days after you receive the reconsideration decision. That is a second 90-day window, triggered by a different letter. Read the tribunal’s current deadline instructions and submission requirements as soon as the new decision arrives.

If another person will represent you at the tribunal, follow the tribunal’s representative requirements. Giving someone permission to talk to Service Canada is a separate matter; Service Canada’s page links its consent-to-communicate form. Do not assume one authorization automatically covers both organizations.

Common mistakes to avoid

• Using the wrong clock: Service Canada’s OAS/GIS page says 90 days from receipt of the decision letter.
• Sending an unsigned paper request: its paper instructions require a signature and date.
• Sending only “I disagree”: explain the decision and why you think it should be reviewed, with new information where available.
• Skipping straight to a tribunal assumption: reconsideration is the first step described by Service Canada.
• Mixing program processes: CPP disability and EI pages use separate instructions.

Related guides

• Change Service Canada direct deposit for OAS, CPP or EI
• CPP disability reconsideration — a different process
• EI reconsideration — a different process

Rules and process basis

This guide follows Service Canada’s OAS pension and benefits reconsideration page, checked 2026-09-26. Its 90-day window, covered benefits and submission routes are program-specific. The tribunal is a separate second stage. Service Canada’s live instructions and the individual decision letter control what to send; the examples here only explain the pathway.