If you are looking to have your fingerprints taken for the United States Postal Service (USPS), there are a few places you can go. The first place is to a law enforcement agency, such as the FBI or the Department of Justice. These agencies will be able to take your fingerprints and store them for you in a database. You can also take your fingerprints to a commercial fingerprinting company.
These companies are typically located in major cities and offer more convenient hours and more accurate fingerprinting. The final place to have your fingerprints taken is at a local post office. This is the least convenient option, but it is also the cheapest.