There are a number of reasons that your net pay can change over the year, including:
- Changes to your compensation or receipt of bonuses, etc., can increase your income.
- Receiving certain non-cash benefits that are subject to withholding may reduce your net pay as more tax is withheld from your salary.
- Once you reach your maximum contributions to Canada’s social security system in the year, your take home pay will increase as those social security contributions are no longer applicable. However, you will likely see a reduction of your pay in January of the following year as the contributions begin for the new year.
No, social security contributions in Canada are mandatory and you cannot have them returned to you.
You will retain the credit for your CPP contributions and be able to claim a government pension upon reaching the retirement age, however it cannot be cashed out early.