> ## Documentation Index
> Fetch the complete documentation index at: https://docs.qonto.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Payment Reminders

> What every partner needs to know before automating payment reminders

Reminders send automated emails to a client on your behalf, anchored on the invoice due date. Before integrating, five things are worth knowing up front — the endpoint reference pages cover each in context, this page brings them together.

## A Client Has at Most One Reminder Configuration

`client_id` is unique across a reminder configuration. Creating a reminder for a client that already has one **replaces** it — `send_to`, `copy_to_self` and the entire `rules` array are overwritten. There is no error on a repeated `POST`; it's the normal way to update a configuration in one call. See [Configure payment reminders for a client](/api-reference/business-api/expense-management/client-quotes-notes/reminders/create-a-reminder).

## Updating Replaces the Entire Schedule

[`PUT`](/api-reference/business-api/expense-management/client-quotes-notes/reminders/update-a-reminder) works the same way as create: send the complete `rules` array, not just the rule you want to change. Any rule omitted from the payload is removed, and rule ids are never returned, so there is no way to reference an existing rule to patch it individually. Read the current configuration with [`GET`](/api-reference/business-api/expense-management/client-quotes-notes/reminders/retrieve-a-reminder) first if you only mean to change part of the schedule.

## The Three Operators

Each rule is anchored on the invoice due date and fires relative to it:

| Operator | When it fires                          | `offset_days`          |
| -------- | -------------------------------------- | ---------------------- |
| `on`     | On the due date itself                 | Not accepted — omit it |
| `before` | `offset_days` days before the due date | Required, 1–999        |
| `after`  | `offset_days` days after the due date  | Required, 1–999        |

A configuration can have between 1 and 5 rules, in any combination of operators.

## Default Email Copy

There is no endpoint to fetch email templates. If a rule omits `email_body`, Qonto sends this default copy based on the rule's `operator`:

| Operator | Default subject         | Default body                                                                                                  |
| -------- | ----------------------- | ------------------------------------------------------------------------------------------------------------- |
| `on`     | An invoice is due today | Hello,<br /><br />The following invoice is due today. If it has already been paid, you can ignore this email. |
| `before` | An invoice is due soon  | Hello,<br /><br />The following invoice is due soon. If it has already been paid, you can ignore this email.  |
| `after`  | An invoice is overdue   | Hello,<br /><br />The following invoice is overdue. If it has already been paid, you can ignore this email.   |

`email_title` always has to be set explicitly — only `email_body` falls back to this default copy.

<Info>
  These defaults are localized in the recipient's language; the table above shows the English copy.
</Info>

## Removing the Invoice Automation Add-on Deletes Every Reminder

If an organization's Invoice Automation add-on is removed, every client's reminder configuration in that organization is deleted immediately, and this **cannot be undone** — the configurations have to be recreated one by one. This applies regardless of whether the reminders were created via this API or the Qonto app. Build for this if you cache reminder state on your side: a `404`/`403` on a reminder you previously created is expected after an add-on change, not a bug.