You can customize invoice numbers when creating standalone invoices through the REST API.

When you create standalone invoices through the REST API, you can use the invoiceNumber field to input a customized invoice number, for example, `6LU5F8NW00001`. A typical use case is to keep the original invoice number when importing invoices from other billing systems into Zuora for easy cross-reference and reporting. Things to note when using this field:

• Format requirements:

  • Max length: 16 characters

  • Acceptable characters: a-z, A-Z, 0-9, -, _,

• Must be unique.

• Only available in the request body of the Create a standalone invoice and Create standalone invoices operations. Operations to update standalone invoices are not supported. Subscription invoices are not supported.

• When an invoice with a customized invoice number is deleted, the system will change the value by adding a random suffix, for example, from `CUSINV00000001` to `CUSINV00000001_14230a434ea`. This behavior ensures that if you use the same invoice number again, it is still unique in the system.

• Avoid using the system default prefixes , prefixes for internal use , or any customized prefixes you have configured because that might have a numbering conflict and cause issues with bill runs and subscribe/amend. To resolve the conflict if it happens, go to Billing Settings > Define Numbering and SKU Formats > Define Prefixes, Numbers and Sequence Sets to identify the prefix in conflict. For more information, see Configure prefix and numbering for billing documents .

  • Change the Prefix to a new one; Or

  • Change the Starting Document Number to a value greater than the current value.