Thanks, seeing the data is so much easier to know what is happening

No you cant add e33 to another number to get the result in e33 as excel doesnt know what e33 was prior to the latest 2 numbers

in my opinion you have 2 choices, have another cell to do the addtion and the type in back to E33 (which is rubbish) or create another sheet (or column on the same sheet) for the data entry then its a simple sum formula then copy paste speical on teh last day of the month - or even better a sumif

See the data on sheet2 and the 2 formulas in E & F

Attached Files

Circular ref problem_purfleet.xlsx (11.4 KB, 9 views)