Before renting a car, see if you're already covered by your personal auto insurance or by your credit card

(CNN) -- At the rental car counter, travelers must decide if they want to accept or decline accident coverage offered by the rental company, but they should be aware that they may already be covered by something they're probably carrying: a credit card.

It's likely your personal car insurance will cover the loss if you are in an accident or the rental car is stolen. The credit card is another coverage possibility.

"Credit card companies are always offering different benefits, one of those being car rental insurance," said Chris McGinnis, a business travel consultant for CNN.

The coverage goes into effect when you use your credit card to pay for the rental.

"We offer car rental loss and damage insurance, which is actually excess insurance, meaning that it kicks in after any insurance you already have ends," said Emily Porter, a spokeswoman for American Express.

Some cards also cover your deductible.

To access the coverage, just make sure you're using a credit card; Most rental car companies won't accept debit cards as pre-payment.

And, remember that coverage varies greatly from card to card and that, in most cases, your credit card insurance won't cover everything.

"The credit card coverage covers you for property damage to the automobile, not the liability that would be yours if you injured someone," said Thomas Finn, a spokesman for Avis.

Check with your charge card company before renting to get a full understanding of your coverage.

Based on a report from CNN's Business and Travel and Beyond. The segment appears weekdays on Early Edition at 7 AM (ET) and on Morning News at 10 AM (ET).