Fun Fact that might be useful to some of our users. This is a question that one of the user noted that might be of interest to QuickBooks Online users:
"if an invoice was created in the system assigned it the number 0010, if i delete that invoice, i notice that the next invoice that the system generated is the number that comes after, which is 0011, but the invoice was deleted so, shouldn't 0010 be available again, or this a quickbooks question?"
QuickBooks do not re-use old invoice numbers after you have deleted them to prevent conflict. To use the deleted invoice number, you have to manually edit the invoice number in QuickBooks itself. To do so, Custom transaction numbers must be enabled.
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