The following page describes how to make a customs payment to revenue.
If you import a vehicle to Ireland from outside the EU (UK, Japan etc.), you are required to complete a customs declaration and clear customs. You will need a customs agent to complete the declaration for you. CustomsDeclaration.ie offers a personalised online customs agent service for people importing vehicles to Ireland.
For more details go to Request a Customs Declaration.
Before submitting a customs declaration you need to transfers funds to your customs account to cover the VAT and customs duty owed on the goods. If you have insufficient funds in your customs account the customs declaration will not process successfully.
The following is a guide which describes how to make an online payment in ROS: