Purchase your traveler's checks from a bank or company that has offices at your travel destination so you can visit a local office to get them replaced.
Sign the checks right away, preferably while you're standing at the teller window where you've purchased them. If you ordered your checks over the Internet, sign them as soon as you remove them from the mail.
Keep your receipt and the serial number of each check in a safe place that's separate from the checks themselves. Also keep the number you should call to have the checks replaced and the address and phone number of any local offices at your destination.
Report the loss or theft of your traveler's checks to the police. You may need to have a police report before your checks will be replaced.
Call the number given to you by the issuing company if your checks are lost and stolen. You can usually reach them 24 hours a day. Provide the serial numbers of the stolen checks. You will be asked for information that will allow you to receive replacement checks while at your destination.