Tag Heuer has been a leading maker of timepieces since 1860. Known for their innovative design and construction, they have graced the wrists of notable people throughout history. It's no surprise that Tag Heuer watches do not come cheap. If you have recently purchased a Tag Heuer watch, completing your warranty registration is a step towards protecting your investment. You will need to find out your watch's model number to complete the process.

Turn your watch over so that it is face down.

Look at the back of the timepiece. There are two numbers. The first is your watch's model number (sometimes called reference number). The second is your watch's serial number. While each watch style has the same model number, no two watches have the same serial number.

Determine your model number. The number begins with two or three letters followed by five digits. It will look like "XX00000" or "XXX00000."