Thanks again NBVC

I have managed to copy the rows down and input the data in several sheets and it works.

I even added extra sheets and got them to work too.

Now, I have not managed to get it to work in another workbook which is identical. I tried copy and paste and I have also typed exactly the same formula in the correct cells.

What is it that needs to change to get it to work in the other workbook. I cannot see the identifier that relates the formula specifically to my test workbook.

Rob