Are you talking about a prequalification letter, a preapproval letter or the actual loan commitment? When you start to make offers, most Realtors and their Sellers will require a prequalification letter. This basically states that the loan officer has seen proof of income, assets and a credit report. And, based on that information the loan officer believes that the prospect will be approved for a loan up to a certain amount, at a no more than interest rate and will note the type of loan proposed, FHA, VA or conventional. A preapproval letter is given when all of the prospects information has been verified, an underwriter has looked at the file and has approved what she sees. A preapproval letter is also subject to some future conditions, allthough these conditions are less than those seen on a prequalification. A loan commitment happens when the underwriter has both complete information on the prospect and The contract and title commitment for a particular piece of property. If the underwriter likes what she sees up to this point, she will issue a conditional commitment subject to other items such as appraisal, updated financials and so on. The length of time for a conditional commitment depends strictly on the lender the prospect has chosen. Some are "backed up" and take a very long time, others are more efficient and take much less time. Generally, you will see a mortgage banking company move much faster than a national bank.