This protects the buyers. If the buyers try to get a loan but can't, they don't have to complete the purchase. In this case, their deposit is usually returned. There are steps buyers can take to add muscle to a pre-qualification letter. Buyers should ask their mortgage person to run a credit check.
Bad credit is one reason loans are denied.
The pre-qualification letter should state that the buyers' credit was checked and was acceptable to the lender. Sellers who receive a purchase offer accompanied by a pre-qualification letter with no mention of a credit check should include a provision in a counteroffer that requires the buyers to provide proof of satisfactory credit review within a few days after acceptance of the contract. Sellers should also require the buyers to submit a completed loan application to a lender within several days of acceptance. Just because the buyers' credit was checked doesn't mean that the loan approval process has begun. The approval process doesn't start until the buyers complete a loan application and submit it to their lender.