What is the difference between a transaction counter height and a work surface height on a reception desk?

The transaction counter (42") is the raised front panel visitors approach. The work surface (29"–30") is behind it where the receptionist sits. ADA units add a third surface at ≤36". Confusing these when ordering is a common mistake. FindOfficeFurniture.com lists all surface heights in each product spec — call 888-719-4960 if you want us to confirm the heights before you order.