Help with look up function

[Rubyroadbike]

Hello 👋🏻
Have a client list "master" spreadsheet which shows client value against individual account number

Have upto date client values for each account in new spreadsheet

How do I use look up function to find new value and add it to master spreadsheet?

Thanks!

[#2]

@Rubyroadbike 

If you're on 365, this sample might work for you.  Please see attached.

[#3]

Hi Patrick, appreciate taking the time to reply.

The master sheet on your sample has a function which assume is locating the account number?

I am looking to use the common data in both my sheets (eg account number) to identify new client value and pull this through onto the master against the client number

Any further suggestions would be helpful.