Brexit jargon buster

Published on
4 min read

We offer explanations of 10 key terms to help build a more detailed understanding of the Brexit issues that still need to be resolved.

We offer explanations of 10 key terms to help build a more detailed understanding of the Brexit issues that still need to be resolved.

1. Acquis communautaire

A useful French phrase to describe the entire body of EU law – a complicated mixture of case law, legislation and regulations of various kinds that is binding on all member states. It forms the legal underpinning of the single market and is due to be translated wholesale into UK law at the point of Brexit – subject to some significant adjustments which are still being debated in Parliament.

2. Customs partnership/customs union

All EU members (plus one or two other countries) are members of the EU customs union. Under that arrangement there are no internal tariffs and common external tariffs are set for imported goods. Members of the EU customs union cannot negotiate separate trade agreements in their own right.

A customs partnership is the name given to a plan devised by UK civil servants which would allow goods to move between the EU and the UK without the need for customs checks. The UK would be free to set its own tariffs for goods destined for the UK market, and would apply the EU’s tariffs for goods in transit to the EU via the UK. It is far from certain whether this proposal would be acceptable to the EU, and there is currently no clear backing for the plan from the Conservative cabinet.

3. Cherry picking

The name given by the EU’s negotiators to an attempt to participate in the single market on a sector by sector basis. Closely related to “having cake and eating it” which describes the wish to retain the benefits of the UK’s current relationship with the EU (eg frictionless trade) without accepting the burdens (eg freedom of movement). The EU Commission has been consistently clear that neither will be allowed.

4. Freedom of movement

One of the “four pillars” of the single market, this is the principle which allows nationals of EU member states the freedom to move to any part of the EU to work. It also includes the right to bring their families to live with them. It is argued that one of the key messages of the vote in favour of leaving the EU was that these freedoms should be curtailed.

5. Hard Brexit

While not exactly a tightly-defined term, a Hard Brexit is taken to involve leaving the single market and the customs union and retaining a minimal level of regulatory alignment. By contrast, a Soft Brexit could involve a high degree of regulatory alignment and staying in a customs union, if not the single market.

6. Non-tariff barriers

The single market is not simply about eliminating tariffs, but also about eliminating other barriers to trade, such as different regulatory requirements or rules on product safety. Often non-tariff barriers are regarded as more onerous for businesses than tariffs. There is currently a debate about how many of these non-tariff barriers could and should be eliminated in the UK’s new relationship with the EU.

7. Regulatory alignment

This is the principle of minimising non-tariff barriers to trade by maintaining common standards. There are various degrees of regulatory alignment, depending on whether exactly the same standards are applied with a common enforcement mechanism, or whether different rules are applied, but agreement is reached to treat them as imposing equivalent standards. Arguably, the strongest kind of regulatory alignment is only possible if the UK stays in the single market.

8. Third party agreements

The network of agreements between the EU and third countries from which the UK benefits in its capacity as an EU member. These mostly cover trade, but also extend into a great variety of other areas, from aviation to policing and criminal justice. It has been estimated that there are over 1,000 such agreements, most of which will need to be replicated in some way or other at the point the UK leaves the EU.

9. Transition period

This is the period between the point the UK leaves the EU (due to take place in March 2019) and the point it leaves the single market and customs union (expected to happen at the end of 2020 unless other arrangements are agreed). The UK Government prefers to call it a standstill period. It will preserve the status quo to allow time for a new relationship between the UK and the EU to be negotiated and implemented, though many think that the planned transition period is not sufficiently long to finalise all the necessary arrangements.

10.Withdrawal agreement

Currently we have “political agreement” on the most of the key terms of the UK’s withdrawal, including the rights of EU citizens, the “Brexit bill” and the transition period. These terms will be incorporated into a formal withdrawal agreement. This will be a legally binding text which will need to be ratified by the EU and UK Parliaments later this year. Currently in draft form, it already runs to well over 100 pages.


Mills & Reeve Sites navigation
A tabbed collection of Mills & Reeve sites.
My Mills & Reeve navigation
Subscribe to, or manage your My Mills & Reeve account.
My M&R


Register for My M&R to stay up-to-date with legal news and events, create brochures and bookmark pages.

Existing clients

Log in to your client extranet for free matter information, know-how and documents.


Mills & Reeve system for employees.