An 18-month reprieve from state toll fines and overdue balances will come to an end Sept. 1, Texas Department of Transportation officials said this week.

The reinstatement of fines only affects customers with outstanding debts on TxDOT-operated tollways, which in the Houston area only includes the Grand Parkway, and holders of a state-issued TxTag, which is different than the local EZ TAG but operable with all local toll roads. Other notable state toll roads are SH 130 in the Austin area and the DFW connector between Dallas and Fort Worth.

The return to assessing late fees comes despite TxDOT not fully accepting the outsourced system managed by Xerox.

“TxDOT has reviewed and accepted 99 percent of the Xerox system,” TxDOT spokesman David Glessner said. “Xerox anticipates completing the remaining items over the next two months.”

Officials suspended toll fines effective March 1, 2015, as the state migrated to the private contractor. The five-year contract started in mid-2014, but by early 2015 drivers were complaining of late or inaccurate bills, poor customer service and tolls on their accounts that they did not use.

“I called and called and called,” said Sharon Moore, 60, of Katy, in February 2015. “Finally, I just gave up and paid it.”

Moore received a bill for using a TxDOT toll road in Dallas in November 2014, despite not being in Dallas, or driving her car for three weeks of that month.

Thousands of TxTag customers faced similar problems. TxDOT fined the company more than $300,000 for poor management of the system, and refunded $1.7 million in erroneous tolls billed to customers. The agency also suspended all late fees.

With the system operating better, but not perfectly, state officials are reinstituting fees.

“The decision to resume late fees was based on customers having ample time, 18 months, to resolve their account status and TxDOT having sufficient time to address its previous billing issues,” Glessner said.

Depending on where the late fee was in the process when fees were suspended, unpaid tolls could go immediately to court or drivers could receive a statement alerting them of the late toll payment.

No billing system of TxTag’s size will be error-free, Glessner said.

“Over the past 18 months, TxDOT has made changes and enhancements to make the billing system better, and we continue to look for ways to improve the customer experience,” he said.

During those 18 months, however, skepticism and frustration has set in with some drivers regarding tolls. From billing woes to bad customer experiences to higher tolls, many are starting to lash out.

“I don’t use them anymore,” said David Tallet, 46, of Spring.

The last straw for him, he said, was billing issues he had two years ago related to an expired credit card on his Harris County Toll Road Authority account. While he said he understood it was his error, which he caught only after receiving a monthly bill the following month, the process of rectifying it left him chafed and angry.

Others have similar stories. Kevin Woodworth, 28, changed vehicles in April and mistakenly was one digit off when he told the county toll road authority his new license plate number. A frequent toll road user from Champion Forest to the Memorial area, Woodworth soon racked up a delinquent toll bill of $911, mostly made up of $37 fines for each time he drove through a tolling station.

Eventually, by fighting hard enough and demanding to talk to supervisors in the customer service department, he got the fees waived in June.

“I was on the phone with HCTRA for close to five hours messing with this,” Woodworth said. “They did not have an answer for why I was only notified after racking up over $900 in fees.”

Like TxDOT officials, HCTRA has said it works to reduce errors and deal with billing issues. Recently, HCTRA redesigned its website so EZ TAG users could maintain more of their account information online.