---
title: "Invalid deduction: definition | Rex glossary"
description: "A deduction the customer isn't entitled to under the agreement, such as a duplicate claim, an expired discount or a penalty for something that didn't happen."
canonical: https://www.rex.inc/glossary/invalid-deduction
---

# Invalid deduction

A deduction the customer isn't entitled to under the agreement, such as a duplicate claim, an expired discount or a penalty for something that didn't happen.

Invalid deductions are recoverable revenue, but only if someone proves they're invalid, with documentation, inside the customer's dispute window.

Because each one is often small, they're easy to write off. Tracking them by reason and customer shows which are worth contesting and which problems to fix at the source.

How Rex helps

Disputes and deductions

Deductions investigated, documented, then resolved or contested.

[See how it works](https://www.rex.inc/disputes)

## Related terms

- [Deductions management Validating, resolving and recovering the amounts customers withhold from payments, from promotional allowances to shortage and damage claims.](https://www.rex.inc/resources/glossary/deductions-management)
- [Reason code A standard label given to a deduction or dispute, such as pricing, shortage or damage, that records why the customer didn't pay in full.](https://www.rex.inc/glossary/reason-code)
- [Write-off Removing an invoice balance from accounts receivable because it won't be collected, charging it to bad debt expense or the allowance for doubtful accounts.](https://www.rex.inc/glossary/write-off)
- [Debit memo A document that increases what a customer owes after the original invoice, for example to correct an undercharge or add a fee.](https://www.rex.inc/glossary/debit-memo)

Next step

Accelerate your receivables operation with Rex

A short walkthrough of agents working your accounts under your guardrails, with your team on the exceptions.

[Learn more](https://www.rex.inc/learn-more)

[Back to the glossary](https://www.rex.inc/glossary)