Up to 1,500 motorists overcharged on the M1 motorway are to get a refund by the end of the month.
Transport Infrastucture Ireland says electronic tag customers were overcharged around €6,000 after being double-charged for journeys on the route at Gormanstown in Co. Meath.
The issue arose when drivers who paid their toll and left the motorway were wrongly charged a second fee, even though they returned to M1 within a three-hour period.
Michael Nolan from Transport Infrastructure Ireland told the Oireachtas Transport Committee they will be reimbursed shortly.
He said: "The operator has engaged with the various tag providers, and others involved in the overall electronic tolling system so as to ensure that customer tag accounts affected by this issue are credited as soon as possible.
"We are confident that this will be achieved by the end of January."