How to file Self Assessment online — step by step

Create a free account

Use Get started on Self Assessment Software. Create your organisation and login. No card is taken to start preparing a return.

Choose a practice organisation if you file for clients, or an individual organisation if you file only your own return. You can sign in later from any modern browser on phone, tablet or desktop.

• Register with name, email and password — takes about a minute
• Pick “I file my own return” or “I file for clients”
• Email verification may be required before you enter the desk
• No payment method is collected at sign-up

Tip: You can draft the whole return before paying. Filing is when the charge (or credit) applies.

Get started registration

Open the taxpayer and tax year

Individuals work on their own return. Practices add a client, then open the Self Assessment tax year you need to file.

Each filing is one taxpayer × one tax year. The UK tax year runs 6 April to 5 April. Online Self Assessment is normally due by 31 January after that year ends.

• Individuals: your return is already set — open the tax year
• Practices: add the client, then open their SA year
• Status shows Draft, In review, Approved or Filed
• You can keep prior years on file for reference

Tip: Have the National Insurance number ready. Add the Unique Taxpayer Reference (UTR) when HMRC has issued one.

Enter personal details

Complete step 1 of the SA100 hub: name, date of birth, address and contact details that HMRC expects on the main return.

NINO and UTR are encrypted at rest and only revealed inside your signed-in organisation. Public pages never load taxpayer data.

• Match the name and address HMRC holds where you can
• Enter date of birth and contact details early — other pages rely on identity
• Add NINO (and UTR when you have it) before you file
• Save as you go — the hub keeps Draft status until you move on

Tip: Wrong personal details are a common reason returns get queried. Check spelling before you leave this step.

Tick what applies this year

Tell the desk which income and pages apply — employment, self-employment, UK property, partnership share, capital gains, foreign income, and more.

Only the pages you tick appear on the year hub. You do not fill every SA form if you do not need it. You can change “what applies” later if your year is more complex than you first thought.

• Employment → SA102 (and elected-office variants if needed)
• Self-employment → SA103 (short or full) / Lloyd’s SA103L
• UK property → SA105 · Partner’s share → SA104
• Capital gains, foreign, trusts on the personal return, residence — when they apply

Tip: Mixed years are normal: employment plus property, or trading plus dividends, can sit on the same SA100.

Complete the SA pages you need

Work through SA100 topics and each attached page. HMRC box numbers sit on the fields so the online return matches the paper form language.

Partnerships can run the full SA800 pack in the same product, then copy allocations onto each partner’s SA104. Paper-style PDFs are available for completed pages when you need a printout.

• Enter income and expenses page by page — figures save as you work
• Self-employment short vs full pages follow HMRC rules for your size of trade
• SA100 also covers savings, dividends, pensions, Gift Aid and student loan where relevant
• Partnerships: SA800 → statement → copy to SA104 on personal returns

Tip: If a box is unclear, stay on that page — the calculation updates when the linked figures are in.

See every form on the desk

Preview the tax calculation

Open the combined tax calculation and SA110 summary. Check income, allowances, Income Tax and National Insurance before you decide to file.

From Reports you can also open an SA302-style estimate, detailed schedule, payment note and tax letter (email available). The estimate is not an official HMRC SA302 until HMRC issues one after filing.

• See estimated tax due or refund for the year
• Review Personal Allowance and how income is taxed
• Check payments on account suggestions on SA110
• Print or save the schedule and SA302-style estimate for your records or lender

Tip: Still preparing free — change a figure, recalculate, and only pay when the bill looks right.

What is an SA302?

Use the filing desk

Move to the filing desk when the figures are ready. Fix readiness checks, sign the declaration, then review and approve before submit.

Practices can email a secure client-approval link so the client confirms the figures. Status moves Draft → In review → Approved → Submitted. You can unlock a return to edit before it is locked for filing.

• Green checks show what is complete; open items block submit
• Sign the SA100 declaration before filing
• Practice workflow: prepare → review → approve → file
• Optional client approval link for practice filings

Tip: Do not rush this step. The readiness list is there to catch missing pages and unsigned declarations.

Pay when you file, then submit to HMRC

Pay for that tax year (individuals) or use one filing credit (practices), then submit from the filing desk. Keep filing status and reports in your workspace.

Published list prices exclude VAT: Employment & investment £39, Self-employed & property £49, Partnership £69. Accountant credit packs start from 10 credits for £179. Drafting never uses a credit. Amendments for the same tax year after payment are included.

• Individuals: one payment per taxpayer tax year at file
• Practices: one credit = one client tax year at file
• Submit from the desk after payment / credit is applied
• You still pay any Income Tax and NI due to HMRC separately

Tip: Software fee ≠ tax bill. The filing fee is for the desk; HMRC still collects the tax you owe.

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