Hello there, @qunuholdings. Is the Custom transaction numbers option turned on? Also, do you have an integrated app with a different format?
QuickBooks Online follows the pattern of the last saved transaction. If you manually edit the number or if your integrated app imports an invoice with a different format, the system adopts that as the new sequence.
To fix this, simply create a new invoice and manually type the correct sequential number into the Invoice no. field. Once you save it, QuickBooks will learn the new starting point and automatically number the following invoices sequentially.
To prevent this from happening again, you can navigate to Gear > Account and Settings > Sales and toggle Custom transaction numbers to Off. This locks the field so the system continues numbering numerically in the background.
If you have any other concerns, please click Reply.
