Suppliers

I was entering all my invoices and accidentally entered the wrong name (from other invoice). Now the supplier is linked to an incorrect vAT number. How can I change the supplier's name, because it doesn't match the invoice? When I try to change it, the computer tells me that I have already created it, but it is under the wrong name.

Go to Relations - Suppliers - type in the name and then edit it using the three dots on the side.