The two-stop, three-minute shuttle service is one of only two Tube lines that runs completely underground, the other being the Victoria line.
TfL said: “It’s full-line branding, from moquette seat fabric and signage to maps and experiential spaces, all right in the heart of London’s business district.”
Moquette fabric is the durable, woollen seating material that is used in upholstery on Tube carriage seats, while an experiential space is described by TfL as a “pop-up presence for sampling and distribution in a pre-approved station space”.
TfL said: “Millions of professionals and decision-makers travel this route every year. Now, your brand can own the journey.”
Previous money-making marketing schemes on London Underground have created controversy.