The Customs and Excise Office is an organization primarily responsible for the enforcement of maritime law throughout Gielinor. Stationing themselves in many of Gielinor's more significant ports and coastal settlements, they are largely responsible for suppressing illegal activity at sea.
In nearly any large urban port, the Customs and Excise Office holds some degree of power. Inspecting ships before they leave port, confiscating contraband, and arresting pirates are just some of the Customs Office's jobs.
- Rock Island Prison - A large prison off the eastern coast of Karamja, Rock Island Prison holds those prisoners that need to be kept under maximum security. Here, hundreds of pirates are imprisoned beneath the island.
- Rimmington Customs Office - A small office in the Asgarnian town of Rimmington, where many of the Customs' activities are performed.