What is a bad debt?

Claudia AinsleyWritten byClaudia Ainsley
Reviewed byMatt Leeburn
Updated 26 Aug 2026

A bad debt is an amount owed to your business, usually an unpaid invoice already counted as income, that you cannot recover despite reasonable efforts and so write off.

Also known as: uncollectible debt, unrecoverable receivable, irrecoverable debt

Key points

  • Typical causes: a customer goes into liquidation or bankruptcy, a debtor cannot be traced, or a court judgment cannot be enforced.
  • The ATO allows a deduction if the amount was included in assessable income, the debt is genuinely bad and you took reasonable recovery steps.
  • If you reported GST on the sale, you can adjust it on the BAS for the period in which you write the debt off.
  • Any amount recovered later is assessable income in the period you receive it, and GST must be accounted for again on the recovered amount.

When a debt becomes bad

Accounting treatment: write-off or provision

Tax and GST treatment

Example

Not to be confused with

Write-off
a write-off is the accounting entry that removes an unrecoverable amount from the books; a bad debt is the unpaid customer debt that gets written off
Non-performing loan (NPL)
a non-performing loan is a lender's classification for a loan in serious arrears; a bad debt is a trade receivable that has become unrecoverable

Frequently asked questions

When can I write off a debt as bad?

Once you have taken reasonable steps to recover it, such as reminders, a formal demand and collection or legal action where that makes sense, and you hold evidence that it is unlikely to be paid. Debtor bankruptcy or liquidation, an untraceable debtor or an unenforceable judgment are the usual triggers. There is no fixed waiting period.

Can I claim a tax deduction for a bad debt?

Generally yes, if the amount was previously included in your assessable income, the debt is genuinely bad, you have taken reasonable recovery steps and you have records to support the claim. Accruals-basis businesses claim in the year of the write-off. Cash-basis businesses usually cannot claim because the income was never returned.

Do I need to adjust GST when a customer does not pay?

If you reported GST on the sale, yes. When you write the debt off you adjust the GST on the BAS for that period, which reduces the GST you owe. If the customer later pays some or all of the debt, you account for GST on the recovered amount in the BAS for the recovery period.

What evidence does the ATO want for a bad debt?

Contemporaneous records that show the debt existed and that you tried to recover it: the original invoice and terms, statements of account, demand letters and call logs, collection agency reports, court judgments and any bankruptcy or insolvency notices. Inadequate evidence is a common reason claims are disallowed.

What happens if I recover a debt I already wrote off?

Treat it as income. The recovered amount is assessable in the period you receive it, to the extent you claimed a deduction, and if you previously adjusted the GST you account for GST on the recovery in that period's BAS. Record it clearly so income is not misstated.

Go deeper

Sources

This article is general information only and is not financial advice.