Cash Basis vs Traditional Accounting for UK Sole Traders
Compare cash basis and traditional accounting, see how invoice timing changes profit, and understand records, eligibility, switching, and Making Tax Digital.
Last reviewed: 11 August 2026 · Editorial policy
The core difference
Cash basis focuses on when money moves. You normally record sales when the customer pays and expenses when you pay the supplier. Traditional accounting, also called accruals accounting, focuses on when income is earned and costs are incurred, even if cash moves later.
The choice changes timing rather than turning private or disallowed costs into allowable expenses. Both methods still need complete, accurate records and appropriate adjustments.
| Question | Cash basis | Traditional accounting |
|---|---|---|
| When is a sale recorded? | Usually when payment is received | When the sale is earned or invoiced |
| When is an expense recorded? | Usually when the bill is paid | When the cost is incurred or the bill relates to the period |
| Unpaid customer invoices | Usually absent from income until paid | Included as debtors, with bad-debt rules where relevant |
| Unpaid supplier bills | Usually absent until paid | Included as creditors when they relate to the period |
| Stock and work in progress | Simpler treatment for many businesses | Year-end quantities and values normally required |
| Finance applications | May show less detail about amounts owed and due | Often gives lenders a fuller view of debtors, creditors, and stock |
Worked timing example
Suppose a designer completes a £3,000 project and invoices on 25 March 2027, but the client pays on 20 April 2027. Under cash basis, that income would normally fall into 2027/28 because payment arrived after 5 April. Under traditional accounting, it would normally fall into 2026/27 because the work was earned before year end.
Now suppose the designer receives a £600 software invoice on 28 March and pays it on 10 April. Cash basis would normally record it in 2027/28; traditional accounting would normally match it to 2026/27 if that is the period to which it relates.
Who can use cash basis
Cash basis is the standard method for many sole traders and partnerships made up only of individuals. A business can opt to use traditional accounting instead. Some businesses and circumstances are excluded, and limited companies use company accounting rules rather than this Self Assessment cash basis.
Traditional accounting may be preferable where the business carries significant stock, offers long customer credit, uses complex finance, needs detailed management accounts, or expects lenders and investors to analyse amounts owed and due.
Records needed under each method
Both methods require records of income, expenses, supporting evidence, and business/private splits. Traditional accounting additionally needs reliable year-end records for unpaid sales, unpaid purchases, stock and work in progress, bank balances, capital introduced, and drawings.
A bookkeeping system can capture invoice dates, payment dates, and categories even when the tax return uses cash basis. That extra detail can improve credit control and business decisions without changing the tax method.
Switching methods
Switching can create one-off adjustments so that income or expenses are not counted twice or missed. Debtors, creditors, stock, capital items, and existing finance arrangements may all need transitional treatment.
Do not simply change a software setting after year end. Record the old method, transition date, adjustment calculation, and treatment used on the tax return. Material transitions are a sensible point to get professional help.
Making Tax Digital does not choose the method for you
Qualifying sole traders and landlords within Making Tax Digital for Income Tax must create digital records and send quarterly summaries through compatible software. This digital obligation is separate from the choice between cash basis and traditional accounting.
Choose software that records both invoices and payments cleanly, preserves evidence, and supports the accounting method used in your return. Review the setup before the first quarterly submission rather than waiting until year end.
Frequently asked questions
Is cash basis the same as using a cash book?+
Not exactly. Cash basis is a tax method for recognising income and expenses. A cash book is simply a record. Modern software can track invoices, bills, and payments while still producing a cash-basis tax report.
Can a limited company use cash basis?+
Not under the Self Assessment cash-basis rules in this guide. Companies prepare accounts under company law and applicable accounting standards.
Does cash basis mean I can ignore unpaid invoices?+
They may not yet be included in taxable cash-basis income, but tracking them remains important for credit control, cash-flow planning, and checking when payment is eventually received.