I need to prepare report on weekly basis, so I have made a transfer sheet and filled with formulas, whenever I plug the new data in a sheet and in the destination sheet, I have my formulas . But last time when I plugged the data, I deleted the old data and plugged in the new data in the same sheet, my formula started to showing #REF. I had to reenter the formulas, what was the reason? Any thought? What can I do to prevent this mishap in the future?