Will EU nationals need a UK visa way after Brexit

All publicly made statements, from both sides, have made it clear that no change for short stays, in the form of visas, is considered desirable.

The Citizens’ Rights and transition portions of the Withdrawal Agreement reflect only the area of long term stays and not short term stays.

The Political declaration setting out the framework for the future relationship between the European Union and the United Kingdom (22 November 2018) states:

IX. MOBILITY
...
52. In this context, the Parties aim to provide, through their domestic laws, for visa-free travel for short-term visits.
...

At present, there are no signs that any changes relevent to short term stays are being taken into consideration from the British side.

From the European Union side, Proposals for a Regulation amending Council Regulation 539/2001 have already been made.

Once the Withdrawal Agreement (or a no-deal Brexit) comes into effect (expected 01.02.2020 CET), in Part 1 of Annex II, the following will be inserted:

“United Kingdom (excluding British nationals referred to in Part 3)”;

• thus the 90/180 days rule will apply for British citizens

Should the United Kingdom introduces a visa requirement for nationals of at least one Member State

• Artical 7 of Regulation (EU) 2018/1806 shall apply

which would start the process for the introduction of a visa requirement of British citizens should no reasonable solution be found.

What will UK travellers to the EU have to do?
Under the Brexit deal, EU citizens and UK nationals will continue to be able to travel freely with a passport or identity card until the end of the transition period in 2020.

After this period ends, the European Commission has offered visa-free travel for UK nationals coming to the EU for a short stay, as long as the UK offers the same in return.

Sources:

• Brexit: No visa but Britons will pay €7 to travel to EU countries
• Political declaration setting out the framework for the future relationship between the European Union and the United Kingdom
• Proposal for a Regulation amending Council Regulation 539/2001 - European Commission (PDF)
• Regulation (EU) 2018/1806
• EU visa reciprocity (2018-12-19)
  • Bulgaria, Croatia, Cyprus , Poland and Romania have made good progress with regard to the requirements set by the U.S.
• ETIAS Visa - European Travel Authorisation Visa - ETIAS Europe
  • The ETIAS visa is similar to the ESTA of the USA or the eTA of Canada.