When you want to hire a car, your driver licence may be subject to background check, which is an uncomfortable situation.

You might not find out this is happening when you hand over your driver’s license, but most agencies disclose it somewhere on their Web site. (Most importantly they’d claim that you already acknowledged this when signing the policy form).

Alamo, Avis, Budget, Dollar, Hertz and Thrifty all check their customers’ driving records through Department of Motor Vehicles (DMV) databases — at least sometimes.

“I’m not sure that it’s done every single time, but enough that it warrants being included in our policies,” said Jason Logan, a spokesman for Dollar and Thrifty. Among the major car rental companies, Enterprise is an exception to this trend. “We do not run a D.M.V. check on drivers,” said Christy Conrad, an Enterprise spokeswoman. “We inspect the driver’s license to check that it’s ‘facially valid.’ ”

Neil Abrams, president of the Abrams Consulting Group, which works with the car rental industry, said that some companies began doing these checks more than a decade ago, and that over time the technology linking Department of Motor Vehicles records has improved — and gotten more affordable. Even so, he questioned whether companies check every customer for every rental. “There are 100 million rental transactions a year in the industry, domestically,” Mr. Abrams said. “That’s a lot of driver’s licenses that have to be validated.”

Many companies list on their Web site reasons they might reject a customer based on his or her driving record, which include things like operating a vehicle without a license, driving under the influence of alcohol (D.U.I.), driving while intoxicated (D.W.I.), or being involved in two or more accidents in the past 36 months. (A friend found out his driver’s license had been suspended — for unpaid parking tickets — when he tried to pick up a rental car, even before the D.M.V. notice arrived.)

So, the point is, if you’ve had any convictions for driving violations within the last three years, you can check whether your record might prevent you from renting a car by calling a company that provides this service to the car rental industry, TML (800-388-9099). TML charges $9.95 to run a driver background check, though some states do not allow this, including California and Pennsylvania.