Many people use traveler's checks when they are traveling. However, merchants who accept traveler's checks face the risk of being given a fake one. The availability of computers, sophisticated printers and graphics software that can produce reasonable facsimiles of these checks has forced the issuers to add a number of security features to them. All of the major brands, such as Master Card, Visa and American Express have features than can alert the merchant to a fake.
Hold the check up to the light and examine the watermark. It should have a watermark and that watermark should only appear on the front, not the back. Also, look closely at the holographic thread. If it is not there or is not shiny and reflective, the traveler's check is probably fake.
Examine and feel the paper itself. A very smooth or thick paper may indicate a fake check. Also run a finger over the printing, since several brands include raised printing on their checks.
Examine the signature box. If it is smudged or it appears the color is slightly different, the original signature may have been removed and replaced. Require that the check be signed in front of you. Compare their signature and the counter signature.
Check the customer's ID to see that the signature and the information match that of check. If you are unsure, call the contact number for the issuer and confirm the name on the check using the serial number.