Which system is designed to automatically subtract tax from income?

Okay, let's talk about how the UK tax system works when you're employed. The key thing to remember is that the UK government collects income tax in a few different ways, depending on your employment status. When you work for a company as an employee, the most common system used is called PAYE, which stands for "Pay As You Earn." This system was introduced during World War II to make tax collection more efficient. Basically, your employer is responsible for deducting income tax and National Insurance contributions directly from your wages *before* they pay you. They then send this money directly to HMRC, which is the government department responsible for tax collection. So, when you get your payslip, the tax has already been taken care of. Self-Assessment, on the other hand, is for people who are self-employed or have other income that isn't taxed at source. HMRC is the tax authority, not a tax system itself. PAYG is an Australian tax system, so it's not relevant to the UK.