Owners will no longer pay business rates on public toilets, the chancellor has said.
Philip Hammond revealed the policy in his Budget speech, joking it was virtually the only announcement that had not been "leaked".
The relief will apply to any standalone facilities available for public use, whether publicly or privately owned.
The British Toilet Association has estimated that 40% of public toilets have disappeared in the past decade.
More than 600 public toilets across the UK have stopped being maintained by councils since 2010 and in 37 areas major councils no longer run any, according to figures obtained by the BBC.
Local authorities are not legally required to provide toilets, so they are often closed as councils look to cut costs.
Public toilets have traditionally been liable for business rates in the same way as other non-domestic premises such as shops and offices.
MPs groaned as Mr Hammond made a string of toilet jokes, including saying that local authorities could at last "relieve themselves".
The chancellor also promised to help High Street shops by cutting business rates by a third for all retailers in England with a rateable value of £51,000 or less.