The Driver and Vehicle Agency (DVA) in Northern Ireland has closed 12 MOT test centres after the discovery of faulty equipment.
It is hoped that the faults issue will be resolved before the end of the day.
MOT centres have closed because of faulty equipment.
The DVA said it will contact affected customers to reschedule tests.
“DVA is currently carrying out checks on vehicle lifts in its MOT test centres, following the identification of faults," said a spokesperson.
"This is precautionary and to ensure the safety of staff and customers.
It is anticipated that these inspections will be completed today and any necessary repairs will be carried out as soon as possible.
"As and when test centres have been inspected and any necessary repairs completed, they will immediately become operational."
“At present, there are limited tests being carried out at most MOT centres and appointments are being rescheduled while inspections and repairs are completed.
Mallusk is the only test centre not carrying out car and light vehicle tests; heavy goods vehicles and bus tests remain unaffected."
The spokesperson added: "The DVA is making every effort to contact customers to reschedule appointments and will prioritise customers who require an immediate test.
“All other test centres remain open and customers should attend their MOT appointment unless contacted by DVA.
"DVA sincerely apologises for the inconvenience caused. It is working to resolve this issue as quickly as possible.”