I am stuck on trying to figure out how to number rows sequentially based off the data in another column. My report contains a column of invoice numbers, and each invoice could have multiple rows of data that correspond to the same invoice number, and each invoice needs to have its own control number. In my example I have manually changed the control numbers to the way I want them to display, but the original file has the control number as 1 for each invoice. I am not experienced in using formulas, so any help is greatly appreciated!!