EXpressToll, the automated toll-collecting system on E-470, Northwest Parkway and I-25 Express Lanes, will start charging account holders $7 when clerks have to reconcile a violation.

The change, effective Aug. 1, is a result of an increasing number of customers failing to update their account information.

When a vehicle passes through a toll plaza, a picture is taken of the license plate.

A violation can be triggered if the equipment at a toll plaza fails to read the transponder, a device allowing for a deduction of the toll from a prepaid account.

In that case, a clerk must examine the photo of the plate to determine if it belongs to an account holder.

Violations occur most often when EXpressToll customers move their transponder to another car that isn't listed on their accounts, get new plates and fail to update their EXpressToll information, or get a new car and don't register it on their accounts.

The processing fee had been waived until now.

Jo Snell, spokeswoman for the E-470 Authority, which operates EXpressToll, said it won't charge multiple fees for an offending car that passes under more than one toll plaza.

A trip to Denver International Airport from Highlands Ranch, for instance, passes through three plazas for total tolls of $5.75.

But if violations occur on multiple days, a fee would be charged for each day, she said.

"This is not a money-making venture," Snell said.

"We had been giving customers a break for so long when they didn't abide by the rules, which include making sure we have your correct plate number, correct address and things like that."

Reasons for EXpressToll violations

Even if you have a valid EXpressToll account, you can get hit with a violation if you don't keep your information current. Here, according to the EXpressToll people, are the top reasons customers get violations:

Driving a car without your transponder.

Failing to file a change of address when you move.

Moving your transponder to a different car.

Selling your car but not transferring title.

Low battery in your transponder.

Getting a new credit card but not updating it with EXpressToll.

Allowing your credit card to expire.

Getting a new car and not adding your new license plate to the account.