Drivers disqualified from driving in Northern Ireland and the rest of the UK will automatically be banned in the Republic from next April.
The new initiative was agreed at last week's British-Irish Council meeting. A reciprocal penalty points system is also in the pipeline, but will not be introduced until later in 2008.
One-sixth of drivers caught speeding in the Republic last year escaped penalty points because they were registered in Northern Ireland.
Drivers in Northern Ireland, the rest of the UK and the Republic all require 12 penalty points before they are disqualified. Points are awarded for everything from speeding to using a mobile phone while driving - but different points are allocated for the same offences in some instances.