Maximize Your Tax Savings: The Importance of Writing Off Bad Debts Before Year-End

Many UK companies pay more Corporation Tax than necessary each year. This often happens not because profits are higher, but because businesses miss a simple, legitimate adjustment before the year ends: writing off bad debts that are genuinely irrecoverable.

Bad debts can be confusing for small and medium-sized businesses. Directors often hesitate, saying things like:

• “We might still recover it.”

• “Let’s wait another year.”

• “They’ve promised to pay.”

• “We haven’t taken legal action yet.”

  
  

Yet UK tax law and accounting standards provide clear and practical guidance on this matter. Understanding when and how to write off bad debts can unlock valuable tax savings.

What UK Law Says About Writing Off Bad Debts

The key legislation is the Corporation Tax Act 2009.

In plain English:

• A trading debt that becomes wholly or partly irrecoverable can be deducted for Corporation Tax purposes, as long as it is properly written off in the accounts.

• The tax rules look at commercial reality, not whether you have gone all the way through formal legal processes.

  
  

There is no requirement that:

• The customer must be in formal liquidation.

• Court proceedings must have started or completed.

• You must have a court judgment.

  
  

If the debt is commercially irrecoverable and correctly reflected in your accounts, tax relief is generally available (subject to some special rules for connected parties).

When Can You Deduct a Bad Debt for Tax?

To claim a bad debt deduction, three main conditions must be met:

1. The Income Was Previously Recognised

The sale must already have been:

• Included in turnover, and

• Subject to tax in either the earlier or the current period.

  
  

If you never recognized the income (for example, a pro-forma, or something invoiced in error and reversed), there is no taxable profit to relieve.

2. The Debt Is Genuinely Irrecoverable

You don’t need to prove legal impossibility, but you must have strong commercial reasons to believe the debt cannot be recovered. Common examples include:

• The customer has gone into liquidation or bankruptcy.

• The customer has ceased trading.

• Repeated attempts to collect the debt have failed.

• The customer has disappeared or cannot be contacted.

The key question: Would a reasonable businessperson conclude that recovery is no longer realistic?

3. The Debt Is Written Off in Your Accounts

This is crucial.

If the invoice still sits in trade debtors with no adjustment, there is no valid tax deduction.

Typical accounting entry for a full write-off:

• Dr Bad Debt Expense

• Cr Trade Debtors

  
  

Without a proper ledger entry, HMRC will not accept a tax deduction, even if everyone “knows” the debt is bad.

Writing off bad debts in financial records

4. Specific Write-Offs vs General Provisions

This is where many businesses accidentally lose tax relief.

Allowed (for tax purposes)

• Writing off a specific invoice in full.

• Writing off part of a specific invoice.

• A specific provision against a named debtor (for example, “Customer X – likely to recover only £2,000 of £5,000”).

Not Allowed (for tax purposes)

• “2% of total debtors” as a blanket provision.

• A general “bad debt reserve”.

• Any percentage-based adjustment not clearly linked to named customers and realistic estimates.

Example:

• Trade debtors: £200,000

• General provision 5% = £10,000

For tax purposes, that 5% general provision is not deductible. Each debtor should be reviewed individually, and only specific bad or doubtful debts qualify for relief.

4. Why Year-End Timing Really Matters

Bad debts reduce your accounting profit. Lower profit = lower Corporation Tax.

Example:

• Irrecoverable invoice: £20,000

• Corporation Tax rate: 25%

  
  

If you write it off before year-end:

• Tax saving = £20,000 × 25% = £5,000

  
  

If you don’t review and it stays in debtors:

• You overpaid £5,000 in Corporation Tax for that year.

• You only get the relief when you eventually write it off – potentially 12 months (or more) later.

A proper year-end debtor review is not just a tidy-up exercise for the accounts. It is a cash-flow decision.

5. Partial Write-Offs Are Absolutely Allowed

You do not have to go “all or nothing” on an invoice.

Example:

• Invoice value: £10,000

• Based on discussions and history, you expect to recover: £3,000

You can reasonably:

• Write off £7,000 as a bad debt, and

• Keep £3,000 in debtors as still expected.

  
  

As long as:

• Your estimate is reasonable and supportable.

• The calculation is debtor-specific (not just a percentage).

• It reflects commercial reality at the balance sheet date.

  
  

Tax relief is given on the written-off amount (in this case, £7,000).

6. Special Warning: Debts Between Connected Companies

When the debt is between:

• Group companies, or

• Companies under common control (for example, owned by the same person or family),

Special rules in the Corporation Tax Act 2009 apply.

In these cases:

• Impairment losses and write-offs may not be tax-deductible in the normal way.

• “Symmetry” rules can apply so that one company’s tax deduction is matched by another company’s taxable credit – or both sides are effectively neutralized.

  
  

If you are looking at writing off balances between connected companies, this is an area that needs careful, specific advice rather than a blanket assumption of tax relief.

7. What Would HMRC Expect in an Enquiry?

Bad debts and provisions are a common focus in HMRC compliance checks.

If HMRC ask about your bad debt deductions, you should be ready to provide:

• Aged debtor analysis at the balance sheet date.

• Emails and letters chasing payment.

• Evidence from debt collectors or bailiffs (if used).

• Insolvency or strike-off notices for customers where applicable.

• Notes from your credit control system or CRM.

• Board minutes, finance meeting notes, or internal authorisation confirming the decision to write off.

  
  

The question HMRC is fundamentally asking is:

“Was the debt genuinely irrecoverable (or specifically doubtful) as at the balance sheet date , and can you show how you reached that conclusion?”

8. Accounting Standards: FRS 102 and FRS 105

Under FRS 102 and FRS 105, trade receivables are financial assets. The standards require:

• An assessment at each reporting date of whether there is objective evidence of impairment.

• Recognition of an impairment loss where such evidence exists.

  
  

Objective evidence includes things like:

• Significant financial difficulty of the debtor.

• Default or delinquency in payments.

• Known insolvency events.

  
  

For companies, tax generally follows the accounts:

• If your financial statements correctly recognise a specific impairment or write-off in line with FRS 102/105, the starting point is that this will also be reflected in your taxable profits – subject to specific tax rules like the connected-party restrictions.

  
  

This hesitation often leads to overpaying Corporation Tax. Writing off bad debts before year-end reduces taxable profits and lowers your tax bill.

9. Common (Costly) Mistakes Businesses Make

Some of the most frequent – and expensive – errors are:

• “Let’s wait one more year” – deferring the write-off and pushing tax relief into the future for no commercial reason.

• Writing off after year-end – missing relief for the current year, even though everyone knew the debt was bad.

• Claiming a tax deduction without actually adjusting the ledger or accounts.

• Using broad percentage provisions (e.g. 3% of all debtors) instead of debtor-by-debtor analysis.

• Overlooking special rules for connected companies and assuming all write-offs get relief.

These mistakes quietly cost businesses real cash, year after year.

10. A Practical Year-End Checklist

Before you finalise your year-end accounts, build in a structured debtor review:

• Review aged receivables over 90 or 120 days (or whatever is long for your sector).

• Flag seriously overdue and disputed invoices.

• Check insolvency notices or Companies House updates for key customers.

• Consider whether the cost and effort of legal recovery is justified.

• Decide on specific write-offs and partial write-offs on a debtor-by-debtor basis.

• Get board or director sign-off on the final list of write-offs.

• Post all journal entries before signing off the accounts and tax computation.

This one exercise can significantly reduce unnecessary Corporation Tax payments and improve cash flow.

Final Thoughts: This Is Not Aggressive Tax Planning

Writing off genuine bad debts:

• Is correct accounting.

• Is explicitly permitted by UK tax law.

• Reflects commercial reality.

• Improves cash flow by avoiding overpayment of tax.

The real risk for most businesses is not writing off “too early”. The real risk is not reviewing debtors properly, leaving clearly irrecoverable amounts sitting in trade debtors and paying tax on profits that, in reality, will never be collected.

Disclaimer: This article is for general information only and reflects my personal understanding and opinions at the time of writing. It does not constitute legal, tax or accounting advice and should not be relied upon as such. You should obtain professional advice tailored to your specific circumstances before taking or refraining from any action.