What happens to the deposit that was paid by the buyer to the listing brokerage?

After closing, the listing brokerage will apply your deposit to the commission owing to them. If the amount of the deposit is enough to cover the commission, the balance will be returned to you by the brokerage after closing. If the deposit is not enough to cover the commission, your brokerage will ask your lawyer to send the shortfall to them from the proceeds of sale. You should note that commission is subject to HST and as such you should add 13% to the commission amount. 

The detailed calculations for commission are included in a document named Commission Statement. The listing brokerage typically sends the Commission Statement to the seller’s lawyer a few days before closing.