Several cruise homeports and East Midlands airport were given Freeport status in the Budget.
Chancellor Rishi Sunak said Freeports would aid Britain’s competitiveness following Brexit.
The Treasury describes Freeports as “a place to carry out business inside a country’s land border, but where different customs rules apply”.
As well as East Midlands, the Thames, including Tilbury, is included, as are Southampton, Liverpool, Harwich and Felixstowe, plus Plymouth and South Devon.
The Treasury said Freeports would combine different customs rules with “tax reliefs, planning freedoms and support for regeneration and innovation”.