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How to fill in SA103F — the self-employment (full) pages of a Self Assessment return

Form SA103F is the full self-employment supplement to HMRC's Self Assessment tax return (SA100) — six pages covering turnover, a paired allowable/disallowable expenses breakdown, capital allowances, taxable-profit adjustments, losses, and an optional balance sheet, for a sole trader whose turnover was £90,000 or more, or whose accounts don't fit SA103S's simpler conditions.

For a personal representative, it reports the deceased's self-employment income and expenses from 6 April of that tax year up to the date they died (or the date trading actually stopped, if earlier) — never the post-death administration period, which is reported separately, not on SA103F.

This walkthrough covers which form actually applies, the business-details and turnover boxes, the two-column expenses schedule, capital allowances and the route to taxable profit, the basis-period transition-profit boxes that a death-year cessation can trigger in full, the optional balance sheet, and the Class 2/4 National Insurance and provisional-figures boxes worth checking on a final return.

✓ Official source checked 23 August 2026 · GOV.UK last revised this form 6 April 2026SA103F on GOV.UK
Free
United KingdomInformational, not legal or financial adviceOfficial source: GOV.UK
Official form · always current

This is the same official SA103F file HM Revenue & Customs publishes on GOV.UK — the link below fetches the current version live from GOV.UK the moment you click it, so it can never go out of date.

Current version: December 2025 · confirmed on GOV.UK 23 August 2026

This walkthrough takes SA103F field by field, for the version a personal representative fills in on a deceased sole trader's behalf. Every allowable-expense total needs its disallowable portion stripped out again in the mirrored column beside it, and a business that ceased trading on death must bring in the whole of any leftover basis-period transition profit at once, in box 73.3 — there's no future year left to spread it into.

The thing most people get wrong
SA103F pairs every expense total with a mirrored 'disallowable' column — box 20's car costs need the private-use portion stripped out again in box 32, box 29's depreciation needs stripping out in box 44, and so on. HMRC's profit calculation depends on both columns being consistent, not just the first one filled in.

On a final-year return for someone who has died, there's a second landmine unique to this form: HMRC's basis-period-reform rules require ALL untaxed 'transition profit' carried forward from 2023–24 to be entered in box 73.3 in the final year, because a business that has ceased trading has no future year left to spread it into. An executor completing a routine-looking return can easily miss this one-off, death-triggered acceleration.
The form, in summary
Valoren
SA103F6 pages101 fields guided
With Valoren45 minutes
Without Valoren3–4 hours
assembling business accounts, splitting expenses into the allowable/disallowable columns, and working the capital allowances
Deadline
31 Oct / 31 Jansame SA100 dates —
check HMRC re: death
Who Files
Executoror administrator, for
the deceased's final page
£
Fee
Freeattaches to
SA100, no fee
Filed with HMRC
Draws from your Estate File
the records this form is built from
PersonalFinancial Accounts·Business Interests & Directorships·Digital Access Map·Asset Inventory·Income & Outgoings·Civil Dossier·Policy Index·Legal Instruments·Medical Abstract·Property Folio·Succession Plan·Digital Legacy Registry·Funeral & Committal Wishes·Dependent Care & Handoff·Personal Record·RegistryMaster Registry·Renewal Register·People, Authority & Contacts·Designated Places·Kinship & Succession Map·SecureAccess Controls·Recovery Routes·Custody & Contingency·EventsDeath & Estate Activation·Incapacity & Medical Proxy·Absence & Continuity Cover·Access Loss & Identity Recovery·Legal Dispute & Evidence Protocol·Theft & Asset Compromise·Property Damage & Incident Response·Relocation & Address Update Protocol·Separation & Custody Documentation·Business Interruption & Continuity·PersonalFinancial Accounts·Business Interests & Directorships·Digital Access Map·Asset Inventory·Income & Outgoings·Civil Dossier·Policy Index·Legal Instruments·Medical Abstract·Property Folio·Succession Plan·Digital Legacy Registry·Funeral & Committal Wishes·Dependent Care & Handoff·Personal Record·RegistryMaster Registry·Renewal Register·People, Authority & Contacts·Designated Places·Kinship & Succession Map·SecureAccess Controls·Recovery Routes·Custody & Contingency·EventsDeath & Estate Activation·Incapacity & Medical Proxy·Absence & Continuity Cover·Access Loss & Identity Recovery·Legal Dispute & Evidence Protocol·Theft & Asset Compromise·Property Damage & Incident Response·Relocation & Address Update Protocol·Separation & Custody Documentation·Business Interruption & Continuity·
Legal basisStatute

SA103F doesn't create its own filing duty — it's a supplementary page attached to SA100, and the underlying obligation sits in section 8 of the Taxes Management Act 1970, which only bites once HMRC has issued (or should have issued) a notice to file. What it reports — trading income, expenses and capital allowances — is charged under section 5 of the Income Tax (Trading and Other Income) Act 2005.

SA103F is the FULL self-employment page, used instead of the shorter SA103S whenever any of: turnover was £90,000 or more (or would have been for a full year); the accounting period ended before 31 March 2025, wasn't 12 months long, or didn't end within the tax year; there's adjustment income from a change of accounting basis; profits chargeable to Class 4 National Insurance need adjusting; or the business was within HMRC's Managing Serious Defaulters programme during the year. None of those apply, use SA103S instead.

Section by section

The form, section by section.

Before you start, you’ll need:
  • Who Files — In Valoren's context, the personal representative — executor or administrator — completing the final Self Assessment return of someone who was self-employed with turnover at or above £90,000 (or who met one of SA103F's other trigger conditions) at or before death. The PR fills in SA103F as part of the deceased's SA100 for the tax year death occurred in, covering income and expenses up to the date of death — or the date trading actually stopped, if earlier — and marks the accounting-period boxes to show the business ceased. It does NOT cover the estate's own income during the administration period that follows, and it is not the same filing as any return the estate itself might separately need if a business continues trading after death — that is a different consideration, outside the scope of this walkthrough.
  • 6 pages · 101 fields guided
  • Draws from your Estate File — Financial Accounts, Business Interests & Directorships
Section 1

Before you start — is SA103F the right form

SA103F is the full version of the self-employment pages, and it's a legal question, not a style choice. Confirm it actually applies before working through six pages of boxes.

When SA103F applies

Use SA103F rather than SA103S if any of: turnover was £90,000 or more (or would have been for a full year); the accounting period ended before 31 March 2025, wasn't 12 months, or didn't end within the tax year; there's adjustment income from a change of accounting basis; profits chargeable to Class 4 National Insurance need adjusting; or the business was within HMRC's Managing Serious Defaulters programme during the year.

None of those apply — SA103S is the correct, shorter form instead.

What it covers for a personal representative

The deceased's self-employment income and expenses from 6 April of that tax year up to the date they died, or the date trading actually stopped if that came first — filed as part of the deceased's own final SA100, not as a return for the estate.

What it does NOT cover

Income the estate itself earns during the administration period that follows death is reported separately, not on SA103F. Nor does it cover any return the estate itself might need if the business continued trading after death, rather than closing out — that's a different consideration outside this walkthrough's scope.

More than one business, or more than one set of accounts

A separate SA103F set is needed for each business the deceased ran, and for each set of accounts ending in the tax year — one page won't cover two unrelated trades.

SA103F is the full version of the self-employment pages, and it's a legal question, not a style choice. Confirm it actually applies before working through six pages of boxes.

HM Revenue & Customs (HMRC) · SA103F
Section 2

Business details and income — page SEF 1, boxes 1–16.1

The opening boxes set the shape of the whole return — description, dates, accounting method — and the two boxes that matter most for a death: the start/cessation dates and the turnover figure.

Business name, description and address

Box 1 is the business name (skip it if trading in the deceased's own name); box 2 is a description of the business, with special routes noted for the Rent-a-Room and Foster Carer / Shared Lives regimes; boxes 3–4 are the business address and postcode, unless the business was run from home.

Start date and final trading date

The start-date box only applies if the business began after 5 April 2024. The final-trading-date box is the one that matters for a death: if the business ceased in the tax year, the notes say personal representatives should notify HMRC promptly, both to avoid overpaying tax and to correct the deceased's National Insurance position.

The accounting period and method

Two boxes give the accounting period's start and end dates; a further box flags whether traditional accruals accounting was used rather than the cash basis. An accounting date that doesn't fit the standard tax-year pattern is itself one of the reasons SA103F applies rather than SA103S.

Turnover — box 15

Cash received or amounts earned before expenses, including payments in kind, tips, fees and commissions. CIS subcontractors must enter the GROSS amount, before any Construction Industry Scheme deduction made by the contractor — reporting the net, after-deduction figure here is a common and consequential error.

Other income and the trading income allowance

Other business income not already in turnover goes in the next box (for example letting part of business premises). The trading income allowance — up to £1,000 — is mutually exclusive with claiming expenses or capital allowances anywhere else on the form; claiming one bars the other.

The opening boxes set the shape of the whole return — description, dates, accounting method — and the two boxes that matter most for a death: the start/cessation dates and the turnover figure.

HM Revenue & Customs (HMRC) · SA103F
Section 3

Expenses — page SEF 2, the paired allowable/disallowable columns

This page runs two columns side by side: total expenses, and a mirrored disallowable column that strips the private or non-deductible portion back out.

Getting one column right and forgetting the other is the most common mistake on this form.

The total-expenses column

Cost of goods, CIS subcontractor payments, wages and staff costs (excluding the proprietor's own drawings and National Insurance), car/van and travel, rent/rates/power/insurance, repairs and maintenance, phone and office costs, advertising and entertainment, loan interest, bank and financial charges, bad debts written off, accountancy/legal/professional fees, depreciation and loss on disposal, and other expenses — summed to a total.

If turnover was under £90,000

Where turnover was under £90,000 (and the business isn't in HMRC's Managing Serious Defaulters programme), the itemised breakdown can be skipped in favour of a single combined total in the expenses-total box.

The mirrored disallowable column

A second column mirrors the same categories and captures only the private-use or non-deductible portion embedded in each total — private car use, entertaining, the purchase cost or depreciation of an asset (both are disallowable), or the private-use share of a mixed property cost.

HMRC's profit calculation reads both columns together. Filling in a mixed cost like car costs or depreciation in the totals column without also stripping its disallowable portion back out here understates the taxable profit.

This page runs two columns side by side: total expenses, and a mirrored disallowable column that strips the private or non-deductible portion back out.

HM Revenue & Customs (HMRC) · SA103F
Section 4

Net profit, capital allowances and taxable profit — pages SEF 3–4

The arithmetic that turns turnover and expenses into a net profit, the capital allowances that can reduce it, and the adjustments — including one specific to a business that has ceased trading — that convert it into the taxable-profit figure HMRC actually charges.

Net profit or net loss

Turnover plus other income, minus total expenses, gives the net profit or net loss box.

Capital allowances

The Annual Investment Allowance, the 18% main-rate and 6% special-rate writing-down allowances, the zero-emission goods vehicle and zero-emission car allowances, the Structures and Buildings Allowance (and its Freeport/Investment Zone variant), the electric charge-point allowance, and any other enhanced or 100% allowances, each summed to a total capital allowances figure — plus a separate box for allowances clawed back where an asset is disposed of below its remaining tax value.

Additions and deductions to net profit

A balancing charge where assets are disposed of above their tax value, or on cessation; goods or services the proprietor took for their own use, added back; and non-taxable income embedded elsewhere in the figures, stripped back out — netted against the disallowable-expenses and capital-allowances totals to reach net business profit or loss for tax purposes.

The basis-period apportionment box

A specific adjustment applies where the accounting period ended before 31 March 2025, or wasn't 12 months long — relevant on a death-year return where trading stopped mid-accounting-period.

Transition profit — the boxes a death-year cessation can trigger in full

HMRC's 2023–24 basis-period reform created 'transition profit' that normally spreads across several future tax years. For a business that ceased trading — typically true on a final-year return following a death — the notes require the WHOLE untaxed transition profit brought forward to be entered in this year's figures at once, because there is no future year left to spread it into. This is the single easiest thing for an unfamiliar preparer to miss on a death-year SA103F.

Reaching total taxable profits

Losses brought forward from earlier years and any other business income are applied last, to reach the total-taxable-profits figure — the notes stress that this box, and the adjusted-profit box that feeds it, must always be completed even where the arithmetic nets to a small number.

If the year shows a loss instead

A parallel set of boxes on page SEF 4 covers a loss set against other income for the year, carried back against earlier years, or carried forward against future profits — the last of these has limited relevance where the business has ceased and there is no future year to carry it into.

HM Revenue & Customs (HMRC) · SA103F
Section 5

CIS deductions and the balance sheet — page SEF 5

A short box for subcontractors, then an optional balance sheet — only relevant if the business's own accounts already include one.

CIS deductions

The total Construction Industry Scheme deductions already taken by contractors from a subcontractor's payments, plus a box for any other tax already taken off trading income.

The balance sheet is optional

If the deceased's business accounts included a balance sheet, its figures — fixed assets, stock, trade debtors, bank and cash balances, trade creditors, loans, and the resulting net business assets and capital account — are transcribed here. If the accounts don't include one, this whole block is skipped.

A short box for subcontractors, then an optional balance sheet — only relevant if the business's own accounts already include one.

HM Revenue & Customs (HMRC) · SA103F
Section 6

National Insurance and provisional figures — page SEF 6

The last page, plus HMRC's own instructions for what to do when the deceased's final-period records aren't complete by the filing deadline.

Voluntary Class 2 National Insurance

A box to voluntarily pay Class 2 National Insurance where total profits were under the small-profits threshold — it protects the deceased's State Pension and contributory-benefit record for that final year, worth checking on a low, part-year return where the consequence isn't obvious.

Class 4 exemption and adjustment

A box to flag exemption from Class 4 National Insurance, and a separate box to adjust the profits chargeable to it where they differ from the taxable-profit figure calculated above.

The free-text box, and provisional figures

A final free-text box takes any other explanation. HMRC's notes specifically address a personal representative who doesn't have complete final figures by the filing deadline: provisional figures are allowed in a defined set of boxes only — turnover, income, net profit/loss, adjusted profit, taxable profits or loss, and the transition-profit boxes — with the free-text box explaining why provisional figures were used and when final figures will follow. Don't send receipts, accounts or other paperwork with the return unless HMRC specifically asks for them.

The last page, plus HMRC's own instructions for what to do when the deceased's final-period records aren't complete by the filing deadline.

HM Revenue & Customs (HMRC) · SA103F

Many people file SA103F themselves — that is what this walkthrough is for. If the situation behind it has stopped being simple — beyond what a careful person can safely do alone — Signum, Valoren’s own specialist desk, can take it on, and we say so plainly: it starts with a free intake, and if you do not need us, we will tell you. Prefer an independent adviser? STEP and the Chartered Institute of Taxation both keep public member directories, and neither pays Valoren a referral fee.

FAQ

SA103F questions, answered.

SA103F is the full self-employment supplement to the main SA100 Self Assessment return. It reports turnover, a detailed allowable/disallowable expenses breakdown, capital allowances and net profit or loss for a sole trader's business.
SA103F applies where turnover was £90,000 or more (or would have been for a full year), where the accounting period doesn't fit the standard pattern, where there's a change-of-accounting-basis adjustment, a Class 4 National Insurance adjustment, or membership of HMRC's Managing Serious Defaulters programme. If none of those apply, the shorter SA103S is the correct form instead.
The final-trading-date box on page SEF 1 (alongside the accounting-period boxes) is normally the date of death for a personal representative's return — not the tax year end, and not left blank.
It mirrors the main expenses column and strips out the private-use or non-deductible portion embedded in a total — private car use, entertaining, or the private-use share of a mixed cost, for example. HMRC's profit figure depends on both columns being consistent, not just the totals column.
If turnover was under £90,000 (and the business isn't in HMRC's Managing Serious Defaulters programme), the notes allow one combined total straight into the expenses total box instead of itemising each one — though turnover at that level is also one of the reasons SA103F, rather than SA103S, might still be the right form.
It's leftover profit from HMRC's 2023–24 basis-period reform that would normally spread across several future tax years. Where the business ceased trading — as is typically true on a death-year final return — there's no future year left to spread it into, so the notes require the whole remaining amount to be brought into this one year's figures instead.
No. SA103F covers the deceased's own trading income up to the date of death (or actual cessation, if earlier) only. Income the estate itself earns during administration, or any return the estate needs if the business kept trading after death, is a separate matter.
HMRC's notes allow provisional figures in a defined set of boxes only, provided the free-text box on the form explains why provisional figures were used and gives an expected date for the final ones — silently leaving other boxes blank, or skipping that explanation, is not compliant.

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Where this fits

SA103F is one form. The file behind it is the rest.

Every figure on SA103F traces back to the deceased's own business accounts — turnover, itemised expenses split by allowable and disallowable, asset purchases and disposals, up to the date trading stopped.

The Financial Accounts record holds the bank and platform detail; Business Interests & Directorships holds what the business itself was and who ran it, so both are ready to check against whichever box HMRC's SA100 letter is asking for.

HM Revenue & Customs (HMRC)101 fieldsFree to file — it's a supplement to SA100, not a separate submission with its own fee45 minutes with Valoren
Attaches to the main return

This is a supplementary page. It's filed together with the main Self Assessment return, not on its own.

The main return — SA100
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