Pubs and restaurants in some parts of England are being allowed to re-open, but with tougher rules.
Different restrictions are in place in Wales, Scotland and Northern Ireland.
There are also special rules over the Christmas period.
What are the Christmas regulations?
Despite the arrangements for meeting others over the festive period, you will not be allowed to go with your Christmas bubble to hospitality settings, such as pubs and restaurants, or to entertainment venues.
You can meet other people outside your Christmas bubble, but only in line with the tier rules of the area in which you are staying.
What are the rules for pubs in England?
The rules vary across the three tiers from Wednesday. The tiers are reviewed every 14 days.
- In tier one, pubs can open until 23:00 GMT, with last orders at 22:00
- In tier two, pubs and bars can also open until 23:00, but only if they operate as a restaurant. Alcohol can only be served with a substantial meal.
- In tier three, hospitality venues must close apart from delivery, takeaway and drive-through services
What counts as a 'substantial meal'?
In tier two areas - where about 60% of England's population lives - hospitality venues can only serve alcohol alongside a "substantial meal".
Venues will only offer table service, and diners could also be asked to leave once they have finished eating, No 10 has confirmed.
Environment Secretary George Eustice told LBC Radio that Scotch eggs would constitute such a meal, while legislation says it should be at least the main course of a breakfast, midday or evening meal, served at a table.
Up to six people from different households can sit together outside in a pub garden.
Businesses in all tiers are legally required to take customers' contact details, so they can be traced if there is an outbreak. Businesses can be fined up to £10,000 for failing to do this, for taking reservations of more than six, or not enforcing social distancing.
Staff in hospitality venues must wear masks, as must customers when not seated at their table to eat or drink. The penalty for not wearing one, or breaking the ''rule of six'' is £200 for a first offence.
Wedding receptions and wakes - where drinks and food are often served - will be permitted in tiers one and two.
People will be able to have 15 guests for weddings, civil partnerships, wedding receptions and wakes, as well as 30 guests for funerals in all tiers. But wedding receptions will not be permitted in tier three.
What are the new rules in Northern Ireland?
Northern Ireland is in a two-week circuit-break lockdown, which started on Friday 27 November.
Pubs, bars, restaurants, cafes and coffee shops are shut, except for takeaways and deliveries, which must stop by 23:00.
What are the rules in Wales?
Welsh pubs, restaurants and cafes are open, but they will be banned from serving alcohol from Friday.
Under new restrictions, hospitality venues will also have to close their doors to customers by 18:00.
Businesses will, however, still be allowed to provide a takeaway service after 18:00 for food or non-alcoholic drinks.
If they have an off-licence, they can sell takeaway alcohol up until 22:00.
The rule allowing a maximum of four people from four different households to meet in pubs and restaurants will stay in place. That does not include children under the age of 11.
Entry to premises is controlled and you will probably be required to pre-book with details of all group members.
Customers must wear face coverings, except when seated to eat or drink.
Businesses are legally required to take customers' contact details. They can be fined up to £10,000 if they do not do this, or if they take reservations of more than four, or do not enforce social distancing.
What are the rules in Scotland?
Each area of Scotland has been placed in one of five tiers.
Restaurants, pubs and bars can open in regions that are placed in level zero, level one, level two or level three.
In level zero, up to eight people from three households can meet indoors, while in level one, a maximum of six people from two households can meet indoors.
In level two, pubs, bars and restaurants are permitted to sell alcoholic drinks only if they come with substantial meals.
This is allowed only until 20:00 indoors, and outdoors until 22:30.
In level three, alcohol sales are not permitted either indoors or outdoors. Cafes, pubs and restaurants are permitted to serve food and non-alcoholic drinks until 18:00.
And in level four, all hospitality venues must close.
Table service and the wearing of face coverings when not seated by all customers is mandatory in all hospitality venues.
What contact details do I have to provide?
UK pub and hospitality bodies have published guidance for bars and restaurants on how to operate contact tracing.
- Contact details only need to be taken from one person in a group
- The details must be kept for 21 days
- Customers only need to give their name and phone number. Owners should note when they arrive and how long they stay
- Data can be taken in any way - paper, online or during a phone booking