A customer or custumer (in Scotland) is an archaic term for a government appointed official who is empowered to collect taxation in the form of customs duty (import duty, export duty, tariffs, etc.) in certain defined physical locations or jurisdictions.
In England generally the office was sold by the crown as a farm, thus enabling the customer to pay a one-off fixed price for the right to assess, collect and retain as his personal property, as much revenue as the law allowed. Customers were frequently appointed for seaports which received imported goods, for example the Customer of Plymouth in Devon was one such office. In Scotland they were collected by the king's custumars at the ports under the acts of 1424 and 1455, almost all of which were within or dependent on royal burghs.[1]
The appointment was made by letters patent on behalf of the crown, thus the holder was a patent officer.[2] Most patent officers created several deputies who served under them. For example, the Customer of Plymouth appointed his own substitutes at ports covering much of the Cornwall peninsula, including Padstow, St Ives, Penzance, Helford, Falmouth, Penryn, St Mawes, Truro, Fowey, Looe, Saltash, etc.[3]