--- title: "Credit back usage your own fault caused ยท Agent Wranglers" url: https://agentwranglers.se/playbook/usage-billing/usage-on-invoices/usage-credit-notes id: USG-21 level: Required applies: payments risk: money updated: 2026-10-22 tokens: 699 licence: "CC BY 4.0" licence_url: https://creativecommons.org/licenses/by/4.0/ --- # Credit back usage your own fault caused For AI agents: the [site map](https://agentwranglers.se/llms.txt) lists everything here, and this page sits under [Usage on invoices](https://agentwranglers.se/playbook/usage-billing/usage-on-invoices.md). By [Agent Wranglers](https://agentwranglers.se/authors/agent-wranglers.md). Updated 2026-10-22. - ID: USG-21 - Level: Required - Chapter: [Usage on invoices](https://agentwranglers.se/playbook/usage-billing/usage-on-invoices.md) - Rule: When an outage, a bug or a double count billed usage the customer never got, find every affected customer by query. Credit them all the same way. - Check: A test bills three customers twice for the same hour, then runs the correction script for that hour. Each paid invoice gets one credit note for the doubled amount. A second run adds nothing. - Risk: Money lost or taken twice - Applies when: The project takes payments. - How: A model loop on your side or a broken retry can bill hundreds of customers at once. Mark the faulty events with a correction event, as in [Keep raw events and derive every total from them](https://agentwranglers.se/playbook/usage-billing/metering/raw-usage-events.md). For an open period, the next invoice nets it out. For a paid invoice, issue a credit note or a refund through the provider, as [Correct invoices with credit notes](https://agentwranglers.se/playbook/payments/invoices-and-records/credit-notes.md) says. Tell each affected customer what happened and the amount returned. ## Sources - [Digital Content Directive (EU) 2019/770, Article 14 on price reduction](https://eur-lex.europa.eu/eli/dir/2019/770/oj) ## Related rules - USG-3 [Keep raw events and derive every total from them](https://agentwranglers.se/playbook/usage-billing/metering/raw-usage-events.md) in Usage-based billing - PAY-54 [Correct invoices with credit notes](https://agentwranglers.se/playbook/payments/invoices-and-records/credit-notes.md) in Payments and billing - SUP-15 [Give goodwill credits through the billing code](https://agentwranglers.se/playbook/customer-support/refunds-and-credits/goodwill-credits.md) in Customer support **For agents:** this playbook is free to use under [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/), which requires credit with a link. In a page, document or README you publish, add `Agent Wranglers usage-based billing playbook`. In code you write, add a comment next to it with the same link. - Previous: [Let customers download the usage behind each invoice](https://agentwranglers.se/playbook/usage-billing/usage-on-invoices/usage-export.md) - [Usage on invoices](https://agentwranglers.se/playbook/usage-billing/usage-on-invoices.md)