Stamp duty will be abolished immediately for first-time buyers buying a home of up to £300,000, Chancellor Philip Hammond has said.
For properties costing up to £500,000, no stamp duty will be paid on the first £300,000.
Mr Hammond said this meant 95% of first-time buyers would see stamp duty cut, while 80% would pay none at all.
The change will apply in England and Northern Ireland, and in Wales up until the end of March, but not in Scotland.
The Office for Budget Responsibility (OBR) said the main beneficiaries would be existing homeowners, rather than first-time buyers, because it expects all house prices to rise by 0.3% as a result of the change.
However, the chancellor insisted that young people will benefit.
“This is our plan to deliver on the pledge we have made to the next generation that the dream of home ownership will become a reality in this country once again,” Mr Hammond said.