Journey
File your first Self Assessment tax return
A step-by-step learning path for filing your first Self Assessment tax return. Covers registration, getting your UTR, setting up records, completing your return, and paying your tax bill.
Filing your first Self Assessment tax return
If this is your first Self Assessment tax return, follow these steps in order. Start early — registration alone can take several weeks, and you need your Unique Taxpayer Reference (UTR) before you can file.
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Register with HMRC
You must register for Self Assessment before you can file a return. How you register depends on whether you are self-employed, a landlord, or have other untaxed income.
Register for Self Assessment
Who must register, how to register online, and what happens after you register.
Register as self-employed with HMRC
If you are starting self-employment, register for Self Assessment and Class 2 National Insurance at the same time.
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Get your UTR number
HMRC posts your Unique Taxpayer Reference after you register. You need this 10-digit number to file your return and make payments.
Get your Unique Taxpayer Reference (UTR) number
How long it takes to arrive, where to find it, and what to do if it is lost.
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Set up your record keeping
Good records make filing easier and protect you if HMRC asks questions. Start keeping records from the day you begin trading or receiving untaxed income.
Keep business records as a sole trader
What records to keep, how long to keep them, and acceptable formats.
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Understand what expenses you can claim
Claiming allowable expenses reduces your tax bill. Gather receipts and records throughout the year rather than at filing time.
Claim business expenses as a sole trader
Allowable expenses, simplified expenses, the trading allowance, and capital allowances.
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Complete and file your return
File online through your HMRC account. The online deadline is 31 January following the end of the tax year. Filing early does not mean paying early — it simply gives you more time to plan.
File your Self Assessment tax return
Step-by-step filing guide with deadlines, supplementary pages, and what information you need.
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Pay your tax bill
Your tax is due by 31 January. If your bill exceeds the threshold, HMRC also requires payments on account in January and July. Several payment methods are available — allow enough time for your payment to reach HMRC.
Pay your Self Assessment tax bill
Payment methods, payments on account, Budget Payment Plan, and what to do if you cannot pay in full.
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Understand penalties
Late filing and late payment both trigger penalties. Knowing the penalty structure helps you prioritise deadlines.
Avoid Self Assessment penalties
Penalty rates, escalation timelines, reasonable excuse, and how to appeal.