Motor tax is payable on an annual, half-yearly or quarterly basis. The rates applicable to the half-yearly and quarterly options are 55.5% and 28.25% of the annual charge, respectively. These relativities have remained generally consistent since the 1960s.
Each quarterly renewal of motor tax requires the same administrative procedures as the annual renewal process. Any consideration of re-balancing of the charges for non-annual discs must take account of the fact that overheads, both direct and indirect, would increase exponentially if the change were to result in increased volumes of transactions. Aside from these costs, the loss to the Exchequer arising from the elimination of the additional charge for these options has been estimated at just under €53 million, on the basis of 2017 transactions.