nseventeen, the normal way of paying tax on overseas rental income is to pay in that overseas country first.
Using Hungary as an example, if an Irish person earns money from a Budapest-based property, then he is primarily liable for tax in HU before his Irish liability. As a basic example, let's say he pays 25% tax on his Hungarian income. If he pays income tax at the higher rate of 41% in Ireland, then because of the double taxation agreement between IE and HU, he can reduce his Irish tax liability by the 25% already paid in HU and pay only 16% tax on the income in Ireland. (This is a basic example and there are other considerations/deductions, which can be made).