creating unique invoice numbers automatically

Copper Contributor

I can't seem to find the correct formula to have my invoice numbers automatically entered and automatically add 1 to the previous invoice for the "new" invoice number. should be so simple!

2 Replies
This works best if your data are in a table (created using Insert > Table). Let's say the first invoice is in row 2 and you want to start with invoice number 1001. Enter the formula =ROW()+999 Excel will automatically propagate the formula to all existing and new rows in the table.

@CoChic2021chubbrock78 

This code automatically generates unique invoice numbers. It keeps track of the most recent invoice number used and builds upon that to create the next one. The code utilizes a variable named last_invoice_number to store this information. A loop ensures the function keeps generating new numbers. Inside the loop, the last_invoice_number is incremented by 1 to provide a unique value for the new invoice. Finally, the function formats the invoice number as a string with a prefix ("INV-") and leading zeros to guarantee a consistent format (e.g., INV-00001, INV-00002). This approach ensures you have unique invoice numbers for each transaction.