Following ratification of the exit agreement negotiated between Brussels and London, the United Kingdom will leave the EU at midnight (Brussels local time) on 31 January 2020. Negotiations on the future relationship between the EU and the United Kingdom will be completed by 31 December 2020. During this period, previous regulations on the coordination of social security will continue to apply unchanged.
The EU Commission's FAQs on Brexit (PDF, 106 kB, non-accessible)
The Brexit FAQs can also be found on the EU Commission's website