If you migrate an existing business to Wave accounts, or are starting to use wave accounts for your new business. You may need to start your invoices numbers with something other than the default 1. To do this:
When you raise your first invoice using Wave accounts , hold your mouse over the invoice number 1 and you will see a small marker icon. Hit this icon and change the invoice number to the next invoice on your list if an existing business. The next time you use wave you will find that the invoice number has increased by one keeping your sequence.