People across the UK will get free access to high-definition (HD) television programmes but to view these they will have to replace their set-top boxes.

Currently only people who subscribe to Sky or Virgin can watch HD programmes but Ofcom has announced a planned upgrade of digital terrestrial television (DTT) technology.

This will provide extra capacity for four HD channels and other new services can be broadcast free to air. One will be reserved for the BBC.

Broadcasters ITV, Channel 4, Five and Welsh language broadcaster S4C will have to bid for the other three based on what they can offer viewers and how well they can manage the spectrum.

The telecommunications and broadcasting regulator said the first three HD channels will be on air by October to December next year as switchover takes place in the Granada and subsequent regions.

People who don’t wish to upgrade to an HD set-top box don’t have to worry that the upgrade will adversely affect their viewing. The upgrade can take place without the loss of existing television services currently available to viewers on DTT.

Ofcom said the upgrade will deliver major benefits because as well as HD programming, broadcasters will have the capacity to offer other services through the extra capacity.

Digital UK welcomed the news of the upgrade: “Anything that helps the interest in and uptake in digital television is a good thing,” it said.