You should use the CWF1 form to tell HMRC that you’re a sole trader by 5th October in your second tax year. This is so that you register in enough time to submit your Self Assessment tax return, without receiving a penalty for late registration.
What happens after I submit a CWF1 form?
HMRC will issue you with a Unique Taxpayer Reference (UTR) number. You’ll then need to keep business records so you know how much money you earn, and your expenses. These records will help you complete your Self Assessment tax return every year, and HMRC might ask to see them.
What do I need to include on a CWF1 form?
The form will ask you for your personal details, NI number, and the nature of your self-employed business. This includes the business name you plan to trade under, and the address where the business will operate.