You need to pay motor tax if your vehicle is used on public roads. Motor tax discs can be issued for 3, 6, or 12 months, but not for past months. If you pay late, you will be charged monthly arrears at one-tenth of the annual rate.
Rates explained
There are now two systems under which motor tax is calculated for passenger cars.
For private vehicles first registered before the 1 July 2008, motor tax is calculated based on the engine size of the vehicle.
For private vehicles first registered in Ireland on or after the 1st of July 2008, up to and including 31 December 2020, motor tax is calculated on the vehicles CO2 emission levels (NEDC value).
For private vehicles first registered on or after the 1st of January 2021, motor tax is calculated on the vehicles CO2 emission levels (WLTP Value).
Commercial vehicles are always taxed on engine cc.
Motor Tax rates and exemptions effective from January 2021