Source: Sharecast
According to the OBR's Economic and Fiscal Outlook, which was accidentally released early - changes planned will raise £1.1bn by 2029-30.
"From April 2026 there will be an increase in remote gaming duty from 21% to 40% and abolition of bingo duty from its current 10% rate," the OBR said.
From April 2027, a new rate of general betting duty for remote betting will be introduced at 25%. This will exclude self-service betting terminals, spread betting, pool bets, and horseracing.
"The Government has also announced a freeze in casino gaming duty bands in 2026-27 with the usual RPI [retail price index - inflation] uprating thereafter," the OBR said.
The news sent gambling shares lower and by 1245 GMT, Ladbrokes owner Entain was down 2.9% at 725.60p, while Evoke - formerly 888 Holdings - was down 12.4% at 32.75p. Flutter Entertainment was 2.4% lower at 14,405p.
However, Rank Group - which owns Grosvenor Casinos and Mecca Bingo - surged 10% to 118p.
Neil Wilson, UK investor strategist at Saxo Markets, said: "Gambling stocks were among the biggest losers on the FTSE as the hike in the remote gaming duty from 21% to 40% was as bad as feared.
"Bookies were always going to be on the sharp end of this tax-grab Budget."
The OBR is meant to publish its outlook once the Chancellor has finished delivering the Budget. However, the outlook went live on its website too early due to a "technical error".
The OBR apologised for the mistake and said it has initiated an investigation into how this happened.