About the Invoices Settings API

Invoice settings control how invoice numbers are generated for a site. Each site has a single invoice settings entity that's automatically available. No creation step is required. You can retrieve and update the settings at any time.

With the Invoices Settings API, you can:

• Retrieve invoice settings for a site.
• Configure invoice numbering with a custom prefix, suffix, and starting number.

Invoice numbers are formatted as {prefix}{nextNumber}{suffix}. For example, with prefix INV-, next number 1001, and suffix -2024, the invoice number is INV-1001-2024. Only 1 prefix and suffix are active at a time. Each prefix has its own independent counter—switching to a different prefix starts a new sequence for that prefix. If you switch back to a previously used prefix, its counter continues from the highest number already issued for that prefix.

Before you begin

It's important to note the following points before starting to code:

• Only 1 invoice settings entity exists per site. There's no ID field because the entity is unique per site.
• Invoice settings can't be deleted.
• You can only retrieve or update invoice settings. There are no create, delete, or query methods.
• You can't set nextNumber lower than the highest number already used for the current prefix.

Use cases

• Configure invoice numbering for a business

Terminology

• Invoice settings: Site-level configuration for invoice numbering. Only 1 entity exists per site.
• Numbering: Configuration for how invoice numbers are generated, including prefix, suffix, and the next number in the sequence.