Official "Brexit Day" is tabled as March 29th 2019 - 11pm to be precise - after which a new set of rules and regulations will apply to Brits making the move to Spain and EU citizens moving to the UK. Those new rules have not been thrashed out.
But the EU and the UK are expected to agree a transition period which will effectively postpone official Brexit Day for a period of time.
On Monday the EU took little time to agree that the end of the transition period should be December 31st 2020 - although the date will need to be agreed with the British government.
In a statement the EU said: "According to the EU position, during the transition period the whole of the EU acquis will continue to apply to the UK as if it were a member state.
"All existing EU regulatory, budgetary, supervisory, judiciary and enforcement instruments and structures will also apply, including the competence of the Court of Justice of the European Union. "
The landmark Brexit deal that was negotiated on expat rights late last year should therefore apply to Britons who move to Spain before the end of 2020.
That deal guaranteed many existing rights of Britons already in Spain such as healthcare cover for pensioners as well as agreeing the uprating of pensions for retired Britons in Spain.
Crucially the deal also covered anyone who makes the move before the end of March 2019, which prompted many Brits who had dreamed of relocating to speed up their plans to get across the Channel before Brexit.
But if the EU gets its way with the transition period - which is likely as Brussels has got its way on most other points of dispute during the negotiations - then at least those making the move can afford a little more time to get it right.
The move to Spain can take many months due to the time it takes to find the right house and even the right part of Spain to live in so movers will be hoping a deal can be struck quickly on any transition period.
While last year's Brexit deal was heralded by Theresa May's government, campaign group British in Europe, which represents the hundreds of thousands of British nationals living in the EU, called it "a double disaster".
They were angry that Britons who have already moved to the EU and those that come before Brexit Day, were not guaranteed continued freedom of movement to move around the EU in the future.
Kalba Meadows who runs the group Remain in France Together, which is linked to British in Europe told The Local at the time: "This is far worse than we were expecting and hoping for and leaves us as greater bargaining chips than before, as freedom of movement and our other outstanding issues have to jostle with the issue of trade.
"Continuing freedom of movement has been deemed 'out of scope' - and yet this is so important for so many of our members.