Viewers will be able to see all of the BBC's channels on digital satellite without the use of a viewing card, after the corporation ended a deal with Sky Digital to carry its services.
Digital channel BBC Three was launched last month
BBC channels are free on Sky Digital, but viewers have received them either as part of other paid-for services or had to request a viewing card, which unscrambles the digital signal.
From 30 May this year, the BBC's services will be broadcast without encryption so viewers without a Sky card will be able to watch.
The move means the BBC saves an estimated £85m over the next five years, which it currently pays to BSkyB for encryption of the channels.
BBC director general Greg Dyke said the move would "bring new benefits to viewers right across the country".
Regional Channels Go UK-wide
15 BBC One regional services
BBC Two in England
BBC One Wales
BBC Two Wales
BBC One Scotland
BBC Two Scotland
BBC One N Ireland
BBC Two N Ireland
The change, which comes as the BBC's current contract with Sky for carrying its channels runs out, will not affect the existing 6.6 million Sky viewers.
But it will mean the channels will be transmitted from a different satellite to the one presently used.
Mr Dyke said: "It will broaden the appeal of digital satellite and enable as many people as possible to get the BBC's digital channels."
The BBC will use half of the savings to make all of its regional and national channels available to the whole of the UK for the first time.
In order to achieve this, the BBC has offered to pay BSkyB a fee, thought to be in the region of £30,000, to make a one-off change to the electronic programme guide.
Sky subscriptions cost from £12.50 a month
The change would allow people to select which regional version of the BBC channels they wish to see.
If the two sides cannot agree on the fee, the BBC will still go ahead with broadcasting its services unencrypted on digital satellite.
The announcement on Tuesday came as a shock to many media observers.
The BBC said the plan will have "profound benefits for audiences" and is the biggest change to its digital plans since the launch of Freeview, the digital terrestrial service, last year.
In a short statement, BSkyB said: "The BBC's proposals mean that all digital satellite viewers would continue to receive its channels.
"Sky looks forward to negotiating charges with the BBC for the technical services it is requesting."
ITV has welcomed the move.
"We understand entirely why the BBC has felt it necessary to take this course of action and wish them every success," ITV managing director Clive Jones told the Media Guardian website.
Mr Dyke said the plan was not part of a campaign against BSkyB and that the BBC was not trying to set itself up as a rival to Sky.
But he did admit relations between the two companies could be "tense" for a while.
The corporation has now ensured that its channels are available free to both digital terrestrial and digital satellite viewers.
In common with Freeview, viewers will now be able to buy a satellite set-top box, have a dish fitted and then receive a wide range of free channels, including all the BBC's channels, without a subscription or a viewing card.
One of the areas of the deal that remains to be resolved is sport rights.
Currently, BBC Wales and BBC Scotland show rugby and football matches which are not for broadcast to the rest of the UK.
BBC Northern Ireland also shows Gaelic sports.
A BBC spokesman told BBC News Online that the BBC would be talking to rights holders in the coming days.
"We very much hope we can come to some arrangement."
If no deal can be made, Northern Irish, Scottish and Welsh viewers would still be able to watch the matches affected on analogue channels.