I'm from the UK and I outsource some of my work to people in countries outside of the EU and I was wondering how do I deal with end of year TAX return? I for example outsource a job for a client where the client pays me £100 and I pay someone else to do it for let's say £50. Once the job is complete, client pays me £100, I pay the outsourcer via PayPal £50 and keep £50 for myself. How do I prove this to the government? Are PayPal receipts enough? Thanks.