I currently earn a side income for doing freelance work for a business based in South Africa. I'm a UK citizen and a UK tax resident working from the UK, I do the work remotely based from my home in the UK. They pay me monthly via my paypal account in GBP and I need to declare this via a self assessment with HMRC. I'm not paying tax on this in South Africa. Should I be declaring this as personal income or foreign income in the self assessment?