Member States must ensure that the right of establishment of EU national and legal persons in any Member State and the freedom to provide cross-border services is not hampered by national legislation, subject to the exceptions set out in the Treaty. The acquis also harmonises the rules concerning regulated professions to ensure the mutual recognition of qualifications and diplomas between Member States; for certain regulated professions a common minimum training curriculum must be followed in order to have the qualification automatically recognised in an EU Member State. As regards postal services, the acquis also aims at opening up the postal services sector to competition in a gradual and controlled way, within a regulatory framework which assures a universal service.