A shake-up in how on-street parking is charged in Northern Ireland has suffered "teething problems".
People have been wrongly fined and charged and one driver was reportedly wrongly charged £90 for a short parking stay.
The Department for Infrastructure has dropped the ParkMobile application for JustPark to allow people to pay for on-street parking in Belfast, Lisburn and Newry on their phones.
The change will see users pay less for transaction charges.
It is thought fewer than 25 people have been either wrongly fined for not paying for parking when they did, or overcharged.
Some said they were unable to cancel bookings or received error messages that they had started a parking event and therefore unable to start another one.
JustPark blamed "teething problems" and the Department for Infrastructure apologised.
Infrastructure Minister Nichola Mallon said penalty notices issued in error would be cancelled.