There is a federal law that requires mortgage lenders to give prospective buyers an itemized, "good-faith" estimate of their closing costs. Sometimes buyers arrive at the closing with this document in hand and proceed to question each item on the final closing statement that does not match the estimate exactly.
These "good-faith" estimates are just that--estimates. The lender's charges will be fairly accurate, but the charges for attorneys, termite inspections, title insurance, and other items that appear on the closing sheet may vary from the estimate. Some pro-rated items, such as taxes or homeowner's association fees, will also be different if you don't close on the date that was used to calculate the estimate. The purpose of the disclosure law is to give you a ball park figure of your closing costs. But the estimate you are given won't be to the penny--probably not even to the dollar!