There are Income Tax Act maximums that apply to the amount you can purchase, which may vary depending on the type of purchase you make. Your purchase amount is limited to:

• 18% of your T4 earnings for the period you are purchasing, or
• the amount of funds in your registered retirement savings accounts, whichever is lower.

If your registered accounts have an amount equal to or more than the calculated purchase amount, you can contribute the entire purchase amount.

Your purchase amount can come from multiple accounts, but if your registered accounts have an amount that is less than the calculated amount, you can only contribute up to the amount available in your registered accounts.