If you are using the new version, please refer to: How to Customize Sales Invoice Print Layout For Signature Section (New Vers.)

How to Amend Running Numbers for Sales Module Documents

When you delete a document, the numbering sequence may become inconsistent. For example, if a sales document with reference number 100 is deleted, the next document you add will be numbered 101 instead of 100. To fix this issue, you need to adjust the numbering sequence.

1. Click on "My Biztory" settings

2. Click on Sales

3. Type the previous reference number in the document you have deleted

4. You can click on "Get last ref num" to get the updated reference numbers

5. Click on Save