Dealings with UK revenue

I'm trying to register as an agent with UK revenue. However, when I go to enrol for online services it prompts me for a tain number (which we have) but also asks for a UK zip code which we dont have because we're an Irish practice.

I've been on to UK revenue numerous times about this and nobody can seem to help me. Has anyone here done this before and if so can you tell me a way to get around it?

I tried to do this myself when working for an international company, and could never progress it to a conclusion.

Just keep trying to speak to someone............ it's the only thing I can suggest.

I don't understand why they would ask for a TAIN number - this is an Irish tax reference.

They use Tain numbers in UK aswell. It's like banging my head against a wall. I will never complain about Irish revenue again. Each tax head operates independently over there so everything is such a rigmarole that something that's so simple over here is so long winded over there e.g. offset over payment of VAT against PAYE. I could be here all night trying to explain.