Ireland has entered into a driving licence exchange agreement with the UK. Under this agreement, a UK licence holder is permitted to exchange their driving licence for an Irish licence with the equivalent categories.
An exception to this is where a licence issued in another (third) country, that Ireland does not have an exchange agreement with, was previously exchanged for a UK licence. Ireland does not have a licence exchange agreement with Zimbabwe and so a UK licence issued in exchange for such a licence can not be exchanged for an Irish licence.
If a person holds a UK licence where a higher category has been obtained by passing a driving test in the UK in reliance, as a prerequisite, on a lower category which originated from such a third country, then the licence is accepted for exchange.