Many buyers don't know the real meaning between a pre-approval letter and a pre-qualification letter.  This is not totally their fault as many lenders and mortgage brokers make this issue very confusing for different reasons.

A pre-qualification letter simply says that if everything checks out the mortgage broker or lender can get you a loan. These letters usually have many contingencies attached to them that need to be met.  These letters really don't carry much weight because they are given out very freely to make you a customer.  The mortgage broker or lender does very little work on your file before giving you this letter.  Down the road you may be disappointed that you can't get the loan because many conditions could not be met.

A pre-approval letter basically says that everything about you has been verified and as long as the home appraises there is a loan waiting for you.  A lender or mortgage broker has to do some work on your file before giving you a letter like this. 

It is best to get a pre-approval letter from a reputable source so you know where you stand and then you can begin your home search.  Starting your home search with a pre-qualification letter often will lead to much disappointment especially in times like these were financing is hard to secure.