Client: we’ve got a problem with your invoice.

Me: Really? It’s £500 + VAT [sales tax in the UK, currently 20%]. We agreed on all that, look, here’s the order…

Client: Yes, we’re fine with the £500. We’d rather not pay the VAT.

Me: But… We have to. You contracted for a service, I provided it, you pay my bill plus the government’s tax, I pay the government that tax that you give to me.

Client: Yes, but we were wondering if you could simply claim it as an expense. We’d save the 20% and you’d save your tax as well. It’s a win for everyone!

Me: Uh, that’s illegal. 

Client: A win for everyone!