Readers’ forum: Northern Irish business with a contract in Dublin

Irish VAT problem

I have a difficult VAT problem for a client who runs a medium sized window cleaning business based in Northern Ireland.

For the last five years the business has had a lucrative contract with the managing company of a block of flats in Dublin. The managing company is not registered for Irish VAT because its service charges to leaseholders are exempt from VAT. My client has charged 20% UK VAT on these fees.

A competitor in Ireland has reported my client to the Irish tax authorities on the basis that they should be registered for VAT in Ireland and charging Irish VAT. The tax authorities agree and have issued a backdated Irish VAT number to my client from July 2016 when this contract started.

How does my client sort out this problem? Can he reverse the UK VAT paid on returns for the last five...