To change your invoice numbering prefix, go to the invoice editor (>New invoice) and click >Choose next to the Invoice number:
A pop-up will open in which you can change the prefix and set your invoice numbering sequence. Please check our Invoice numbering article for more details.
If you have several recurring invoice profiles, we invite you to read this article: How to change the invoice number sequence on recurring invoices?
If you have only a few, you can follow the Click on your recurring profile > Edit, and Change the numbering sequence, and save.
Any recurring profile will keep the numbering sequence it was created with, until it is edited.