I have two Excel sheets. One with a list of existing customers, and one with a list of potential customers or "leads". These two sheets have different columns than one another, but the phone number column on both are formatted the same. I would like to check the potential customer worksheet against the existing customer worksheet to identify duplicates using the phone number columns in each. In other words, I want to make sure none of these potential customers are already customers of ours.
I have tried identifying duplicates using a new column on the potential customer sheet with no luck based on something I found online but I'm not sure if this would even work? =ISNUMBER(MATCH(G2,'Existing Customers'!G2:G2111,0))