Your retirement benefit payment is based on how much you earned during your working career. Higher lifetime earnings result in higher benefits. If there were some years when you did not work or had low earnings, your benefit amount may be lower than if you had worked steadily.

Hmm... that is a good question...
Being self employed, I don't know the answer to that.

It would be nice if a tax expert would help out on this question.

Dear sir;

I am a Canadian who left Canada around 20 years ago. I only worked and paid Canadian tax for 3 years.

Now I want to return back to Canada to retire.

The question is:

Can I pay a lump sum to Canada Tax so I can be receive retirement benefits