In Canada, an applicant applying for a patent must pay maintenance fees to the government, even when no patent has yet been granted. The first maintenance fee is due 2 years after the patent application is filed, and continues for the life of the patent and/or patent application.
However, just because maintenance fees are due to the government does not mean that anyone can pay them. In Unicorp v. Canada, 2011 FCA 55, a law firm tried to pay the maintenance fee for an patent, but as it was not the appointed agent for patent in question, the payments were refunded and were not applied to the patent. The patent was subsequently deemed to be irrevocably abandoned due to a failure to pay the required maintenance fee. The Federal Court of Appeal affirmed that the patent was irrevocably abandoned due to a failure to pay fees.
It's thus important to remember that while remembering to pay maintenance fees are important, it is just as important to ensure that the person or entity paying the maintenance fee is the appointed agent, or is otherwise an authorized correspondent to the patent or patent application in question. In patent law, having money and paying it to the government isn't enough; who pays the money is just as important.