Most UK corporations will lose easy access to the EU market because of Brexit.

This is judged after Brexit took practical effect, when the transition period ended on 1 January 2021 under the Trade and Cooperation Agreement. 'Easy access' means trading with the EU without the new customs, regulatory or market-access barriers that come from being outside the single market and customs union. True: the UK left the single market and customs union, and most UK companies that sell into the EU (goods and services) faced substantially new barriers such as customs declarations, rules-of-origin checks, regulatory duplication or loss of passporting. Mostly true: barriers were imposed on most such firms but were modest for a notable share of them. Mixed: easy access was lost by roughly half of UK firms trading with the EU, for example only in some sectors. Mostly false: only a minority of firms or sectors (e.g. mainly financial services) lost easy access while most kept near-frictionless access. False: the UK kept single market and customs union access or an equivalent, or Brexit did not happen.

Set before the research began.

1. E1 How Brexit affected the trade of UK firms CentrePiece (Centre for Economic Performance, LSE) · 13 September 2026

   “Our estimates imply that the TCA caused around 16,400 firms (or 14% of EU exporters) to stop exporting to the EU.”

2. E2 Brexit reduced goods exports by £27bn – with smaller firms most affected LSE (London School of Economics and Political Science) · 18 December 2024

   “The TCA did not include tariffs. But it did introduce barriers to trade such as customs checks and paperwork, rules of origin requirements, excise duties, sanitary and phytosanitary checks on the movement of animals and plants, and the need for exporters to prove their products comply with regulations in their destination market.”

3. E3 Brexit reduced goods exports by £27bn – with smaller firms most affected LSE (London School of Economics and Political Science) · 18 December 2024

   “Among firms that continued exporting to the EU, the TCA reduced the average value of EU exports by 30 per cent for the smallest fifth of firms (with six or fewer employees) and by 15 per cent for the middle fifth”

4. E4 Statistics on UK-EU trade - The House of Commons Library House of Commons Library, UK Parliament · 12 June 2026

   “While there are no tariffs on trade in goods with the EU, subject to certain conditions, other barriers to trade are now higher.”

The evidence shows that the TCA brought in new non-tariff barriers to UK-EU goods trade, such as customs checks, rules of origin and regulatory compliance [E2, E4], and that it had uneven effects on exports [E1, E3]. It does not measure how heavy those barriers were for most firms, and it does not cover services trade, so it cannot tell whether "most" firms or only some lost easy access under the criteria.