SEPA - Direct Debit Mandate Setup - Creditor Address Number

On setting up the SEPA direct debit mandate (P743002), on form W743002B there is a tab where you enter the Debtor information.  There is a field called Address Number - Name and you should enter the debtor address number in here.

This then should pull in the IBAN and BIC information setup on this Debtor address number, this however is not happening and on running the R743005 report I receive a number of work center error messages about this Debtor Address number including invalid address number.

Is there a specific address number search type that should be entered in this field?  Basically just want more information about what this field is for as the SEPA Direct Debits application just says the following: