If you do this, don't use Santander as they won't show the references. Co-op do though.
As a reference I use <house number><postcode> or <first 4 letters of housename><postcode>. Keep a list of references on a database or spreadsheet.
It works just fine since I got them to pay into my Co-op account. Because Santander don't show the references, I now have two accounts for one business. Co-op takes the bank transfers and Santander take the cash and cheques.