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Ftax for Businesses

Self Assesments for Sole Traders

Filing a SA100

If you run your own business as a sole trader (including freelancers and side-hustles), Self Assessment is how you report your trading income and claim your costs. This guide explains what to include, how to keep records, and how to file online with Ftax quickly and accurately.

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Ftax for Self Assessments

Ftax Business Self Assessment SA100 (2024/25)

2 Credits
£21.40
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What you report

As a sole trader you’ll include on your SA100:

  • Trading income (invoices/fees you’ve earned)
  • Allowable expenses (your business costs)
  • Capital allowances where relevant (for tools/equipment/vehicles)
  • Other personal items if you have them (bank interest, dividends, pensions, etc.)


Ftax switches on the Self-Employment pages (SA103) during setup so you only see the sections you need.

Cash basis or accruals (which to choose?)

You can usually pick between:

  • Cash basis – record income/expenses when money moves. Often simpler for small businesses and new traders.
  • Traditional (accruals) – record when income is earned and costs are incurred (matching invoices and bills to the right period).

Allowable expenses

Claiming the right costs keeps your tax fair:

  • Everyday running costs: advertising/marketing, software, bank charges, professional fees, insurance, phone and internet (business share).
  • Use of home for business: claim a reasonable proportion, or use HMRC’s simplified flat rate if it suits you.
  • Travel and mileage: either claim simplified mileage or a fair business share of actual running costs (not both).
  • Tools and equipment: usually via capital allowances.
  • What’s not allowed: personal spending and everyday clothing.

You’ll enter totals for each category in Ftax; keep the detail in your records.

Keeping records (simple and digital)

You can keep books in a spreadsheet or use Ftax Cashbook (optional) to record income and expenses during the year. At filing time, bring your final totals into the Ftax form pages.

Store digital copies of invoices/receipts, plus your submitted return, calculation and HMRC receipt.

Getting ready for Making Tax Digital (MTD): keeping clean digital records now will make the transition smoother when MTD for Income Tax applies to you.

Cashbook

  • Low cost online accounting
  • Record incomes, expenses, and other business data
  • Populates the VAT, SA100, SA800, and CT600 forms
Learn more

Payments on Account

If your income-tax bill is above HMRC’s threshold, you may be asked for Payments on Account towards next year’s income-tax/NIC. These are normally due on 31 January and 31 July. CGT isn’t included in Payments on Account. Filing early with Ftax gives you clarity on what’s due so you can plan cash flow.

Common pitfalls to avoid

  • Mixing personal and business costs: claim only the business portion and keep notes of how you worked it out.
  • Double-claiming mileage and fuel: pick one method.
  • Forgetting capital allowances: tools/equipment may qualify even if paid near year-end.
  • Missing NI: remember Class 2/4 – Ftax calculates these from your profit.
  • Leaving it late: early filing reduces mistakes and last-minute stress.

File Now with Ftax

Ftax for Self Assessments

Ftax Business Self Assessment SA100 (2024/25)

2 Credits
£21.40
More Info
Buy Now

Disclaimer

Ftax does not provide accounting, tax, business or legal advice. This guide has been provided for information purposes only. You should consult with your own professional advisors or with HMRC for advice directly relating to your business before taking action in relation to any of the content provided. Ftax Support will only be able to assist you with matters directly concerning the Ftax products and service.

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