Need to add client SSN to spreadsheet based on name.

So I have a spreadsheet from my company's accounting department (Accounting.xlsx) with a list of all clients, including name address and email.

No somewhere else in my company there is a spreadsheet with every customer's first name last name and social security number (SSN.xlsx).

I need to copy the social security numbers from the SSN.xlsx spreadsheet over to the Accounting.xlsx spreadsheet, and make sure the social security numbers get added into the correct records according to the person's name.

My company is very disorganized and I am new to this , take it easy on me.

-Roberto

If both spreadsheets are open, this can be achieved through vlookup.

I've been looking up the INDEX function and was wondering if this would work for me.

It seems to me that VLOOKUP only looks at the first column of a spreadsheet for its "lookup_value". The problem is, I have a first name and a last name that I want to use as the "lookup_value", because there are many duplicates of last names in this table.

INDEX function would work. If you're looking to combine 2 cells (first and last name), you may use the CONCATENATE function on a separate column.