Are you talking to me? I'm originally from the UK and came here when I was 26. When I applied for OAS, I found that I needed 40 years work in Canada to get the full amount but luckily I either had that or close enough to make no real difference. The UK DID NOT top up my OAS. (My OAS then got clawed back because of how much I had earned two years previous!) I get about half a basic UK pension because of the time that I worked in the UK, by buying years of contributions back, and by paying a few years of contributions until I reached the year when I turned 65 after which contributions are not allowed. The Canadian government does not top that up and I have to pay Canadian taxes on it.