On 1 May 2004, both countries became EU Member States, adopting the acquis communautaire. A number of important agreements governing economic matters have been concluded, including the following:
Agreement on the Mutual Protection and Promotion of Investments Between the Republic of Slovenia and the Republic of Hungary (signed in Budapest on 15 October 1996, concluded for a period of ten years, thereafter in force until cancellation; applicable since 9 June 2000)
Agreement between the Government of the Republic of Slovenia and the Government of the Republic of Hungary on the Inclusion of Compulsory Stocks of Crude Oil, Feedstocks and Petroleum Products Stored on Behalf of the Republic of Slovenia in the Territory of the Republic of Hungary (signed in Budapest on 20 November 2002, already ratified by Slovenia)
Convention between the Republic of Slovenia and the Republic of Hungary for the Avoidance of Double Taxation and the Prevention of Fiscal Evasion with Respect to Taxes on Income and on Capital (signed in Budapest on 26 August 2004).