Fact Sheet on Intra-European Union Investor-State Arbitration Cases

Intra-European Union (EU) investor–State arbitration has been a prominent topic in domestic and international policy debates. Recent developments related to the Achmea case put a spotlight on the future of intra-EU disputes based on bilateral investment treaties and the Energy Charter Treaty.

This IIA Issues Note presents statistics and facts on intra-EU investor-State arbitration cases by the end of July 2018.


The overall number of known intra-EU investor-State dispute settlement (ISDS) cases – treaty-based arbitrations initiated by an investor from one EU member State against another EU member State – totalled 174 by 31 July 2018, which constitutes 20 per cent of the 904 known ISDS cases globally.

Most known intra-EU cases were brought against three EU member States: Spain (40 cases), Czechia (30) and Poland (19). Investors from the Netherlands, Germany, Luxembourg and the United Kingdom initiated about half of the known intra-EU arbitrations.

Ninety-five per cent of intra-EU cases were based on investment treaties signed in the 1990s or earlier. About 45 per cent of the cases were brought pursuant to the Energy Charter Treaty (1994).

By 31 July 2018, some 91 intra-EU ISDS cases had been concluded and 83 were pending. Out of the concluded cases, 47 per cent were decided in favour of the State and 27 per cent in favour of the investor, with monetary compensation awarded. The remaining cases were settled, discontinued or the tribunal found a treaty breach, but did not award monetary compensation.

A review of 49 decided intra-EU cases provides information on the following issues: the affected investment, the types of challenged measures, the alleged rationale and the alleged adverse effects of the challenges measures. Annex 2 contains a mapping of principal issues (jurisdiction, admissibility and merits) discussed by tribunals in these cases.