Lengthy queues formed outside several motor tax offices as the deadline approached for registering the non-use of a vehicle.
Dublin City Council said motor tax offices saw large numbers of people registering ahead of the closing of the tax loophole.
The new rules mean a person must tell the Motor Tax Office in advance of their intention to take their car off the road for between three and 12 months in a calendar year.
Previously, owners could retrospectively declare their vehicles off the road and therefore avoid paying arrears.
Around 200 people queued at the tax office in Ballymun in Dublin specifically to register.
Both Clondalkin and Smithfield motor tax offices also reported exceptionally long queues.
Several hundred people waited outside County Hall in Galwa.
There were similar lengthy queues at the county's other motor tax office in Ballinasloe.
Hundreds of people also queued outside offices in counties Cork, Kerry, Limerick and Clare.
The Department of Transport earlier said there would be no extension of the deadline and the timeframe had been well flagged in recent months.
Under the new rules, those making a false declaration of non-use could face fines of up to €4,000 or six months in prison.
The three-month transition period, during which those in arrears must pay the arrears and either take out a new vehicle licence or make a declaration of non-use, ended today.
A spokesman for Kerry County Council said people began queuing outside its Tralee offices at 7.30am, which was two hours before its official opening time.
Last Friday, staff dealt with almost 900 applicants, well in excess of the average daily figure.