Re: Tax
If this scenario relates to the building industry, how is Relevant Contracts Tax (RCT) dealt with? A contractor cannot pay anyone for building work of any description (unless they have a C2) without stopping 35% tax at source. This applies whether the money ends up in Kanturk, Jersey or Timbuktoo. Foreign contractors may be able to claim refunds of part or all of this tax depending on their own situation but they must follow procedures to do so.
Btw, it is extremely difficult for anyone to half-successfully evade RCT unless they construct an elaborate scam or else go around with literally briefcases full of cash in which case they would probably end up with a joint Revenue/CAB investigation into false accounting/money laundering/criminality.