Your Global Entry Known Traveler Number (KTN) is **exactly 9 digits**—the number labeled **PASSID** on the back of your card. [CBP confirms the nine-digit format](https://www.help.cbp.gov/s/article/Article1296).

Enter only those nine digits in the airline’s KTN field. **Leave out the spaces and the trailing letters and numbers**, such as `BC321`.

For example, if the card shows `123456789    BC321`, enter **`123456789`**.