Software: QBO (QuickBooks Online) Singapore
When switch from QuickBooks desktop to QuickBooks Online (QBO), you may prefer to keep the same invoice running number in the QBO as the QuickBooks desktop accounting software. QBO has locked the running number by default to prevent user from editing it, this measure is to prevent duplicate running number if user were to manually entering it.
To change the setting, you may go to the Sales Form Entry preferences and check the “Custom transaction numbers” checkbox.
Once the setting is saved, you will see an additional “Invoice no.” field appeared on the invoice transaction screen. You can amend the number. You can use Alphanumeric in the “Invoice no.” field but subjected to a maximum of 21 characters (I don’t think you will need 21 characters 🙂 )