Secondly - sellers and listing agents for seller's expect a qualified pre approval letter to accompany a purchase offer. So you may as well be prepared in case you see a home and want to write an offer on it that night.
In additition to the wonderful answers previous to this, at times you find out that there are items on your credit report that aren't accurate. Usually it is just one or two items that might cause your lender to not give you the most favorable rate.
This will take some time. It is very important to get this done as soon as you realise you would like to purchase.
RE/MAX Bryan-College Station