RELATED() or LOOKUP()

[kault]

I have two tables. One table is called "Customer", one table is called "Invoice". The relationship is set on the field "primary email address", where the cardinality is Many:Many.

I have a column on the Cusomter Table called Account Name. I need a column on the Invoice table that populates the Account Name. I  just want to bring the account name from the Customer table to the Invoice table. 

I've tried doing this with RELATED() and the field is not an option. I don't know how to do it with LOOKUP.

[mahoneypat · Accepted solution]

Since you have M:M relationship, you can use an expression like this to return the Account Name

AccountName = MAXX(RELATEDTABLE(Customers), Customers[AccountName])

If this works for you, please mark it as the solution.  Kudos are appreciated too.  Please let me know if not.

Regards,

Pat