Cannot Have Shared Bank Account - Employee and Supplier

Summary

We have an employee who shares a bank account with a new supplier we need to create.

Content

We have an employee who shares a bank account with a new supplier we need to create.

When we try to add the bank account to the supplier (site) we get the following error message "A record with this combination of values already exists".

We are able to share bank accounts between different suppliers but can we share with a person?

We urgently need to get a resolution for this.