Toll port

A toll port was an intergalactic way station, shaped like a giant dandelion, that used the money it received to support the Confederation. The Seventh Doctor and Mel commented on the absurdity of having to pay tolls in infinite space since there could be two toll ports on top of each other, and that you could actually travel endlessly and never encounter one. (PROSE: Delta and the Bannermen)

They were the ten billionth customers when they landed at port G715. As a prize, they received a fabulous 50s tour to Disneyland, Earth with Nostalgia Tours. The Chimeron Delta landed at the port and boarded the tour bus. She was followed by the Bannermen, who killed the tollmaster before leaving. (TV: Delta and the Bannermen)

Behind the scenes
It is unclear if there were multiple instance of the toll ports seen in Delta and the Bannermen. However, there were certainly multiple docks. The original script had the Doctor referencing many toll ports but this was cut in draughting. (INFO: Delta and the Bannermen)