Air passenger duty is to be scrapped for children under 12 from May 2015.
From the following year the tax will be scrapped for children under 16, the chancellor, George Osborne, announced.
Airlines and holiday firms have long campaigned for the government to axe the duty, known as APD, on departing flights, which ranges from £13 per passengers for short-haul flights to £97 for the very longest flights departing the UK.
The chancellor had already promised to cut the very highest band of tax on long-haul flights from next year, limiting the levy to £71 per passenger worldwide from 2015, lopping £26 per person from a flight fare to Australia or New Zealand.
With opponents frequently citing the cumulative tax bill for “a family of four”, eliminating the tax for under-12s may eliminate the worst headline figures.
However, the measure is unlikely to satisfy airline demands as the tax is seen as a particular blight on domestic flights – which largely carry adult business travellers who are charged on both legs of a return flight – and the most price-sensitive short-haul budget carriers, where the standard £13 rate of APD is far higher than the margin of profit per passenger.
APD may soon be cut and eventually scrapped in Scotland, after the Smith commission recommended powers to set the tax be devolved, potentially putting English airports at a substantial disadvantage.