Rent-a-Room Relief allows you to earn up to £7,500 per year tax-free from letting a furnished room in your main home. It applies to Airbnb income if you are hosting guests in your own home and living there during the letting period. It does not apply if you are letting a self-contained annexe with a separate entrance, or an entirely separate property. If your gross receipts are £7,500 or below, the relief is automatic and you do not need to file a Self Assessment return for that income. If you exceed the threshold, you must file and choose between paying tax on receipts above £7,500 or calculating actual profit after expenses.