That’s tax evasion though. If you get caught, you’ll find yourself with massive fines and possibly a prison sentence.
HMRC know about these sorts of goings on, and they monitor for it. Remember most countries have reciprocal agreements so they’ll know (eventually) if you have bank accounts abroad. Cash withdrawals from the account are logged – so they’ll have every shred of evidence that they’d need to prosecute. To be honest, it’s even worse than being paid cash in hand, as there is a massive paper trail left behind.
It might take some time for it to catch up with you, but if it does then you’re done for. Is it really worth spending your life looking over your shoulder? That’s my opinion on it anyway…as I said earlier, people really need to understand the difference betweentax avoidance (completely within the law) and tax evasion (illegal).