Applying for CPP and OAS When you first apply to begin your OAS or your Canada Pension Plan (CPP) payments, Service Canada provides guidelines for processing the application.

When should I file the application for the CPP and Old Age Security (OAS)? Can I designate the month I want the payments to start? Congratulations on the milestone birthday coming up.

In both OAS and CPP cases, you can receive up to 11 months of retroactive payments from the date Service Canada receives your application.