Thanks Whatsup, your code worked. It did take me a while to get to it but yes, its almost doing what I want. The only issue is if I leave the cell without entering a value, the code doesn't do anything. I'm realising I was a little too literal in my original question. I'd like the code to respond "leaving the cell" rather than "entering a value into the cell".

Are you able to help with that one?

Many thanks for your help.