In my invoices file I have a global value list to check on a customers paid status.

Value list = yes, no and all.

I have created a calculation field in invoices:

paid_filter & " " & customer_id

The paid_filter is the global field that has the value list.

In the right hand portal relationship I have creaded a calculation field:

Paid & " " & customer_id & "

Match field should be

Paid & " " & customer_id & "

Thank you, you got me on the right track. This is what actually worked:

Paid & " " & dr_id & "