UK HMRC Forms · 2026/27
What is the CWF1 Form? UK 2026/27 Guide (Self-Employed Registration)
What it is
CWF1 is HMRC's standard self-employment registration form. It captures: your personal details (NINO, address, contact), business details (start date, type of business, expected turnover), and any other relevant information (do you have other employment? any partners?). After processing, you get a UTR by post and your self-assessment account is activated.
Who needs this
Anyone starting a UK self-employed business as a sole trader: freelancers, consultants, gig economy workers, contractors not operating through a limited company, landlords with property income above £1,000/year, and anyone earning income outside PAYE that exceeds the trading allowance (£1,000). Limited company directors don't use CWF1 — they register the company separately with Companies House.
When you'll see it
Complete CWF1 yourself when starting self-employment. The deadline is 5 October following the end of the tax year you started (e.g. starting July 2026, register by 5 October 2027). Most accountants advise registering within the first 1-3 months to avoid forgetting and to start NI contributions correctly.
How to get it
Register online via gov.uk/log-in-register-hmrc-online-services. The CWF1 process is now mostly online — paper version available but rare. You'll need: NINO, contact details, business start date, business type/SIC code, expected turnover. After submission, UTR arrives by post within 10 working days typically.
Common issues
Common CWF1 issues: (1) registered late (penalty of up to £100 plus daily charges — file ASAP), (2) wrong start date (use the date you actually started trading, not the date you first thought about it), (3) UTR not received within 4 weeks (call HMRC self-assessment helpline 0300 200 3310), (4) registered but earnings stayed under £1,000 (call HMRC to formally cancel — otherwise self-assessment obligation continues annually).
Recruiter pro tip
If you're going self-employed, register CWF1 BEFORE you start invoicing — even if your first month's earnings will be small. UTR processing takes 10+ working days; without a UTR you can't easily file your first year's return when due. Also: open a separate business bank account before invoicing — the cleanest way to track allowable expenses for the year-end tax return is to have all business transactions on one account.
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