After a Cobra meeting chaired by Tory minister Michael Gove and the first ministers of the devolved nations, it was confirmed people would be able to see family over the festive period.
Applying across the UK, this will include overnight stays and will last from December 23 to December 27.
Confirming the plans, First Minister Nicola Sturgeon urged caution despite the relaxation of measures.
She said: “We know that, for some, contact with friends and family is crucial during this time as isolation and loneliness can hit people especially hard over the Christmas period. The ‘bubble’ approach aims to reduce this impact.
“But we must be clear, there cannot be any further relaxation of measures for Hogmanay. Even this short relaxation will give the virus a chance to spread.
"Our priority is to suppress transmission of Covid-19 and reduce the risk to the vulnerable and those who have spent so long shielding - and that involves abiding by the rules.
“Just because you can mix with others indoors over this time, that doesn’t mean you have to. If you choose to stick with the rules as they are, then you will be continuing the hard work to beat this virus and prevent its spread.”
These bubbles will not be able to be changed and socialising within them will only be allowed in private homes, outdoor spaces and places of worship.
Visiting venues such as pubs or restaurants will not be allowed with that group, but people will be able to hug family members and will not have to stick to social distancing within their bubble.
Each administration will clarify their own rules on support bubbles and extended households in due course.
In England, support bubbles will continue to be counted as one household.
Travel restrictions will also be lifted across the UK for these five days.
People in Northern Ireland are set to be given an extra day either side of the five-day period to allow more time to travel.
Speaking following the meeting on Tuesday, Mr Gove said: “The UK-wide agreement reached today will offer hope for families and friends who have made many sacrifices over this difficult year.
“We know that the Christmas period this year will not be normal, but following constructive discussions between the UK Government and the devolved administrations, families and friends will now have the option to meet up in a limited and cautious way across the UK should they wish.
“In coming to this agreement, we have listened to scientific and clinical advice on how best to minimise the risk and reach a balanced and workable set of rules that we hope will allow people to spend time together at this important time of year.”
A joint statement from the UK Government and the devolved administrations added: “As 2020 draws to a close, we recognise it has been an incredibly difficult year for us all.
"We have all had to make significant sacrifices in our everyday lives, and many religious and community groups have already had to change or forgo their customary celebrations to slow the spread of coronavirus and save lives.
“This cannot be a ‘normal’ Christmas. But as we approach the festive period, we have been working closely together to find a way for family and friends to see each other, even if it is for a short time, and recognising that it must be both limited and cautious.
“In this context, the four administrations have reached agreement on a single set of UK-wide measures to help people come together with their loved ones in a way that is as safe as possible.”
Scottish Secretary Alister Jack welcomed the agreement, which will apply in England, Scotland, Wales and Northern Ireland - all of which are under different coronavirus restrictions.
He said: “I’m very pleased we have secured agreement right across the UK to ensure families can meet, albeit in a far more limited way than usual, this Christmas.
“Christmas has a special place in all of our hearts. It is a time when many of us look forward to spending time with friends and relatives, and many families come together from all parts of the UK.
“This Christmas will not be what we are used to. Because of the virus, it simply cannot be. But a limited easing of restrictions will allow us to see some of our loved ones at this important time.
“More household mixing does mean more chance for the virus to spread, however, and I urge people to be as careful and responsible as possible over the Christmas period.”
Scottish Labour Leader Richard Leonard claimed the plans were “sensible and safe”.
He said: “This will come as a huge relief to people across Scotland, after weeks of speculation and doubt about whether families would be able to spend Christmas together this year.
“We still need to be acutely aware of the fact that there will still be many Scots who face spending Christmas alone.
“Loneliness has surged during the pandemic, with grievous consequences for mental health and wellbeing.”
This week Boris Johnson admitted there would be risks to allowing people to gather over the festive period, declaring it was the "season to be jolly careful".
On Monday the Cabinet Office revealed that ministers from England, Scotland, Wales and Northern Ireland had endorsed a “shared objective of facilitating some limited additional household bubbling for a small number of days”.
An agreement was reached between the four nations following talks on Saturday, but it was emphasised the public would still be advised to “remain cautious”.
Earlier on Tuesday Health Secretary Matt Hancock told MPs this Christmas would not look the same as normal.
The decision comes a month after Scotland's national clinical director Professor Jason Leitch told Scots to get ready for a “digital Christmas”.