# Reference number (PO) or CIF/NIF number on your invoice

## Question

How to add a reference number or PO number on the monthly invoice?

## Answer

It is possible to add a reference number (PO number) or a CIF/NIF number on the invoice.  
  
This option is available via the control panel:  
**Account > Financial > Custom invoice information fields**

Or via this direct link:  
[Invoice Settings](https://cp.openprovider.eu/account/invoice-settings.php)

![image__44_.png](https://openprovider.help/uploads/images/gallery/2026-08/embedded-image-brhijfmg.png)

After adding the information and clicking **Save changes**, these numbers will be present on all future invoices. In case the next invoice needs to contain a new / updated number, make sure the information is updated in the control panel before the new invoice is generated (1st of the month)  
  
Please note that we are **not** able to re-generate past invoices to include these numbers.