As soon as the lender has verified your credit information you should receive the pre-approval letter. So the faster you are able to supply the lender with the information they requested, i.e. bank statements, paycheck stubs, etc, the sooner the lender can issue the letter. Most of my clients receive them in a day or two. If your situation is one that needs more time - for fixxing your credit, or verifying unique assets, etc., then it could take 7 to 21 days. You can also ask for a pre-qualification letter. The pre-qualification letter is one that says based on the information given to the lender by you, you should be able to qualify for a loan/purchase price of XX. The pre-approval letter is a letter stating that the information you have given the lender has been verified, and that you are approved for a specific loan. Even a pre-approval letter will have contingencies, usualy stating the approval is subject to the appraisal, title and purchase contract.