States verify that a CDL or CLP driver has only one such license by:

Question

All U.S. states share information about CDL and CLP licenses in a computerized database. If you apply for a license in one state, a state will check this database to verify that you do not already have one such license in another state.

Accepted Answer

Using a computerized system that links all states.

Answer

Making phone calls to surrounding states.

Answer

Asking the driver.

Answer

Looking through the driver's wallet.