See the attached. I used the technique outlined in http://drawingwithnumbers.artisart.org/customizing-grand-totals-part-2/, with the results of that wrapped in another table calculation to return only one result per customer.
Let me know if this works for you,
Morning Jonathan, so what's the 't' stand for. Happy Labor day.
Happy Labor Day to you, too! I assume the 't' in 'jtd'? Thomas. It's in muscle memory from doing code check-ins awhile back.