- ITV News Political Reporter Shehab Khan explains what lies ahead during this year's transition period.
Britain has left the EU - more than three years after the public voted to leave in a national referendum.
But the UK has a long road ahead before it's finally free from the whole Brexit process.
It has now entered a 'transition period' that's scheduled to continue until the 31st of December.
British Members of European Parliament (MEPs) won't return, and the UK will lose membership of EU political institutions, but the country will - for the most part - stay within the customs union and single market.
That means British regulations will stay aligned with European ones for the rest of the year, but the UK will lose any ability to make or influence decisions inside the EU.
However, from January 31st, Britain has been freed up to make trade deals with other countries around the world.
There's already talk of agreements under discussion with the United States and Japan, but it's the future trade relationship with the EU that's a big focus for government.
Both sides have stressed a free trade agreement is the preferred way forward, but there's a lot of work to be done before December 31st.
March to December: Deciding the future relationship with the EU
March 1st is the date the EU has set for sorting out its own negotiating position with its 27 member states.
After that, the European Commission and the UK will begin a long series of trade talks expected to last until November 26.
A summit will be called in June to provide an update on trade talks. It will also be the last chance the UK will get to request an extension to the transition process - something that Prime Minister Boris Johnson has already ruled out asking for.
In practice this effectively gives the EU and the UK only six months to discuss a future trading relationship, a time frame leaving some European figures sceptical.
Irish Foreign Minister Simon Conveney said the UK was putting itself into a "straitjacket" by refusing to extend the transition process and was expecting a "very intense" negotiation ahead.
If the two sides can't work out a deal by the end of the transition process, then Britain will revert back to World Trade Organisation rules.
This outcome would be the same as a no-deal Brexit.