What is the issue?
If you receive a notification that the number is duplicated when creating a new document (invoice, quotes, etc.), you just need to set up the numbering again.
How to solve it
- Go to Control menu> Settings > Invoicing > Documents
- Select the document type that's returning the error
- Below Document numbering, click on the numbering line
- Insert the correct last number in Last num.
Learn more about document numbering on the platform by reading this article