TFSAs offer an excellent opportunity to grow your investments tax-free (read more on that here). However, the government sets a limit on how much you can contribute. Your TFSA contribution room is determined by the contribution limit for the year (set by the Canadian government) as well as any unused contribution room or withdrawals from previous years since you turned 18. All TFSA contributions made during the year, including the re-contribution of withdrawals made from a TFSA, will count against your contribution room. If you exceed the contribution limit (even accidentally), you could receive a tax penalty from the Canadian Revenue Agency (CRA). Learn more about that what happens if you over-contribute here.