The number of foreign individuals living in the U.K. who don’t pay taxes on offshore earnings fell a second year in a row.

An estimated 78,300 individuals claimed “non-dom” status in the U.K. in 2017-18, down 13% from 90,500 in the previous year, according to data published Aug. 8 by Her Majesty’s Revenue and Customs. In 2016-17, the tax office reported a 23% drop.

  • Non-doms—often the owners of multinational companies and sports teams—are individuals who reside in the U.K. but claim their permanent home is overseas. They don’t pay U.K. tax on foreign income or gains unless they bring...