A mortgage pre-approval is a letter that confirms your ability to qualify for the mortgage you need to buy a home. Written by your lender, the pre-approval verifies that your lender has conditionally approved you to borrow up to a certain amount, based on your income, assets, and other qualifying factors. The pre-approval letter signals to agents and sellers that you’re a serious buyer because you’ve already taken steps toward financing your home before putting in an offer. And because it means you can get your mortgage approved quickly, the pre-approval is one of the best tools for buyers in a competitive market.