What it is A mystery closing cost like a "processing fee," "document preparation fee," "administrative fee," "messenger fee" or "document review fee"

What's so bad The fees sound legit (a document is being prepared, after all), but many are simply padding the lender's bottom line, says Jack Guttentag, a mortgage expert who runs mtgprofessor.com. With so many fee names, you can't always tell what's what.

Ouch! Although lenders must give you a "good-faith estimate" of loan costs within three days of receiving your application, they don't have to stick to it. Junk fees can total a few hundred to several thousand dollars.

What you can do Ask a pro to review your good-faith estimate. For $45, the National Mortgage Complaint Center (866-714-6466 ) will look it over and alert you to excessive or bogus fees. Some lenders, such as Amerisave and E-Loan, quote one figure that includes all fees and points, allowing you to shop according to the bottom line.