Sky viewers must check their TV now as over a dozen channels are removed TODAY

SKY viewers have been urged to check their TVs today as more than a dozen satellite-definition (SD) channels are set to disappear.

It forms part of an industry-wide satellite switch off, which saw the BBC and ITV cull their own SD channels earlier this year.

As HD TVs become the norm, broadcasters are making an effort to free up the airwaves.

All SD channels have an HD twin.

So the channels aren’t really disappearing forever – just their SD versions.

If your TV isn’t HD-compatible, however, then they will vanish for good.

Sky began the first phase of the switch-off in March, when it replaced the BBC’s SD channels with their HD counterparts on program guide.

The second phase, kicking off 29 May, will see a raft of Sky-branded SD channels disappear, including Sky Cinema Family and Sky Sports Football.

Full list of Sky’s SD channels that will disappear:

• Sky Cinema Premiere
• Sky Cinema Greats
• Sky Cinema Family
• Sky Cinema Action
• Sky Sports Main Event
• Sky Sports Premier League
• Sky Sports Football
• Sky Sports Cricket
• Sky Sports Golf
• Sky Sports F1
• Sky Sports Action
• Sky Sports News
• Sky Sports Arena
• Sky Sports Mix
• MUTV
• Sky Sports Box Office

In a last minute announcement, Sky said two of its SD channels – Sky Sports News and Sky Sports Mix – will not close as previously planned.

The U-turn follows concern around these channels being a part of the Sky Signature bundle which requires a paid HD upgrade.

The switch-off means older SD-only boxes will lose functionality by the end of this year.

Fortunately, most people have a Sky Q or Sky+HD box which should mean the impact is relatively low.

However, Sky is offering a free upgrade to Sky Q for affected customers.

Subscribers to these channels will have their subscriptions automatically cancelled unless they upgrade to an HD box.

SD broadcasts will continue for the Republic of Ireland.