The environment minister has said MoT centres will be able to open on Sundays during peak periods from next year.
"I have authorised the Driver & Vehicle Agency (DVA) to avail of the option of opening vehicle testing centres on Sundays," Alex Attwood said.
He was responding to an assembly question from TUV leader Jim Allister.
Mr Attwood said it was likely that only the Belfast test centre would require Sunday opening during the peak period early next year.
The peak period for MoT tests is normally between January and March.
Mr Attwood said demand for vehicle tests had increased almost tenfold since the mid-1980s, and is projected to grow by a further 5% in 2012-13 and on average by 3.5%-4% a year over the next five years.
The DVA has 15 test centres across NI, which currently open for 12.5 hours a day from Monday to Saturday.
Sunday working will be on a voluntary basis for staff.
A number of changes to MoT tests came into force in Northern Ireland in May.
Under the new rules, more than 20 extra checks are carried out on vehicles.