Evening all

I am looking for a steer towards the best method to use for the following problem.

Each month, I am given a sheet, with data of people that are becoming veterans. So I am looking to create a master sheet, which has their details on, also some extra columns that do not come on the initial spreadsheet (person responsible, contact columns).

Master sheet sits there and people have access to the sheet work through it.

Then at the end of the month, a new sheet arrives, it will have some names that are on the master sheet already, but some new. I would then like the excel to upload check the new sheet, people it finds on both, leave, new people added it does not find and then delete the ones it does not find.

Hopefully that makes sense?