The Waterloo & City line (colloquially known as The Drain) is a London Underground line that runs between Waterloo and Bank with no intermediate stops. Its primary traffic consists of commuters from south-west London, Surrey and Hampshire arriving at Waterloo main line station and travelling forward to the City of London financial district, and for this reason the line does not normally operate on Sundays.

What's the best answer to this question: is waterloo and city line open on sunday?
no