Sales invoice sequencing

Hello, This is a question for the QBO program. I am a bookkeeper that does not enter the sales invoices for the client, as he does this himself. I do record credit memo’s such as rebates for customers. When I enter a credit memo I usually use the invoice# with CR on the end, ie. invoice #45108CR. Is there a way for me to start the correct sales invoice # sequence again so that the client doesn’t continue send out invoices 45109CR on it😊? He doesn’t look at the invoice number, so has sent out several invoices with CR on the end.