Hi, I need help regarding an issue in our QB account. We noticed that the same invoice number is being generated for multiple customers.Can you please us to solve ?

If the Custom transaction numbers feature is enabled within your company settings, you or another authorized user can assign any invoice number. This may result in invoices being generated with matching numbers unintentionally.

You can sort this out by opening the draft invoice containing duplicate numbers and manually changing them to unique values to keep your records clean. If it's already paid, leave it as is, but add a unique reference note in the Memo field to ensure you still track and distinguish the transaction internally.

If you want to use a new numbering sequence moving forward and prevent duplicates, create a new invoice, then turn off the auto-transaction numbers feature. Here's how:

1. Go to the + Create menu to make a new invoice.
2. In the Invoice no. field, enter the custom number you prefer.
3. Save and close your invoice.
4. Click the Gear icon and pick Account and settings.
5. Choose Sales, then toggle the Custom transaction numbers off.
6. Hit Save to confirm.

Additionally, third-party sales apps connected to QuickBooks use their own numbering systems, which can override QuickBooks' sequence and lead to duplicate invoice numbers. You can leave these transactions as is for your audit trail, but consider adding a unique reference note for clarity.

In case you're dealing with a different scenario or setup not covered here, please feel free to leave a comment below for further assistance.