This is based on HMRC trying to stamp out what they term as 'False Self Employment'
So, with that in mind, you can see why the rules are shaping up the way they are. The idea of not being employed (neither PAYE or operating under a Ltd co) is what they want rid of.
I'm reasonably sure that to be paid gross you would need to invoice the UK agency under a Ltd company. It seems, from an HMRC perspective, that the company does not need to be UK registered. I had this very discussion offshore (N Sea) with a colleague of mine (based in Asia) last trip. This is pretty much how he saw it also.
Currently it seems that UK agencies are wetting their pants at the changes, as 1)They were brought into force a year sooner than expected and 2) It does appear to put them on the hook for taxes if they get it wrong. This has made them overly cautious overnight.
For that reason I have been hearing (as in here-say) that UK agencies will only take people on if they are Ltd co or PAYE. Certainly that seems to be the case for work in the UK sector.
As for UK ex-pats with proven non residency living and working overseas for a UK agency, it would appear to HMRC as acceptable that you would be paid gross, but as suggested it's a grey area that many UK based agencies will simply not take a risk on.
I do anticipate the list of agencies diminishing somewhat, over the coming years, as many realise that the quick easy buck they thought they were going to make might not be quite so quick and easy!
