The recognition and enforcement of arbitration awards will remain unchanged between the UK and EU/EEA states because the New York Convention (on recognition and enforcement of arbitration awards) operates independently of  the EU/EEA regimes and Britain continues to be a party of the New York Convention.

There will be changes however in civil and commercial cooperation on the recognition and enforcement of court judgments should the UK leave without having reached an agreement with the EU by 29 March 2019:

• Rules of national law rules will apply in the UK and in the relevant EU/EEA member state because the reciprocal elements of EU law will cease to have effect. In the UK, they will be repealed by the UK government.
• The Brussels I Regulation will no longer apply between the UK and the 27 EU States. It is expected that England and Wales will fall back on pre-existing common law rules for the recognition and enforcement of foreign judgments.
• In some cases, bilateral treaties and conventions pre-dating EU members exist between the UK and EU member states. The national law of each EU/EEA state will determine whether  UK judgment can be recognised and enforced in that jurisdiction. (And vice versa for recognition and enforcement in the UK of a foreign judgment from an EU/EEA state)
• Where the parties have made an agreement on an exclusive choice of court, the  2005 Hague Convention will be applied between the UK and EU/EEA states (and other states party to that convention). The UK will accede to this Hague Convention. Note that this convention provides only for the recognition and enforcement of judgments where the parties have concluded an exclusive choice-of-court agreement.
• In relation to Service of Documents and Taking of Evidence, the Hague Conventions will continue to apply.
• The status of ongoing court cases after 29 March is unclear. The rules governing the enforceability of any case decided after that date will cease to have effect. There is a risk that parallel cases may be taken in multiple jurisdictions.
• The Insolvency Regulation will no longer be applicable between the UK and EU27 member states. An insolvency officeholder appointed in the UK will have difficulty obtaining recognition in the EU.
• EU Regulations on service of proceedings will no longer apply, although in most cases it will be possible to rely on the Hague Service Convention.