Combine two list with old and new

I have two spreadsheets: 1st spreadsheet shows client id and client name 2nd spreadsheet shows client Id, client name and client information. Spreadsheet 1 is my list of clients old and new; spreadsheet 2 is my master client list with out the new clients. I want to sort/figure out which items on spreadsheet 1 that are not on spreadsheet 2. I hope this makes since and someone can help me.

Thanks