Consolidate multiple worksheets into one reference cover sheet

Hi There,

I have a workbook that has multiple Invoice worksheets for each subcontractor we use to train our Apprentices.
I would like to have a cover sheet that consolidates all apprentices’ so we know that they have all been accounted for on the invoices. I want this cover sheet to highlight if an apprentice has not appeared on any worksheet Invoice in the workbook. I also want this cover sheet to automatically update when a new worksheet Invoice has been added. I will be setting up the original work book, but will then be sending it out to our managers who don’t have much excel experience, and I pretty much want to them just to be able to print the invoices without touching anything else in the workbook.

I hope I have made myself clear, I have attached a work book as an example.
Thanking you in advance
Excel Forum.xlsx

That is awesome, Thank you so much.

I will work around "YES/NO".

thanks so much again