In order to be admissible, the referred question must either concern a non-uniform application of the law by the boards or, alternatively, a point of law of fundamental importance (see in this chapter V.B.2.3.7). According to Art. 112 EPC, this requirement concerns not only referrals by a board but also referrals by the President, which, however, must in any case concern "different decisions" of the boards (see in this chapter V.B.2.4.1).

In T 154/04 (OJ 2008, 46) the board found that deviating from an opinion given in another decision of a board of appeal or a deviation from national jurisprudence are not per se valid reasons for referral under Art. 112(1)(a) EPC. According to the board, the legal system of the EPC allows for the evolution of the case law, which is not case law in the Anglo-Saxon meaning of the term. In T 15/01 (OJ 2006, 153) the board did not consider a referral to the Enlarged Board necessary, because only one previous decision of the boards deviated from its own conclusion as to the exhaustion of priority rights. In T 248/88 the board also held that a single and isolated non-uniform decision did not qualify under Art. 112(1)(a) EPC.

In T 712/10 the board stated that the Enlarged Board does not have the power to ensure uniform application of the law between the boards of appeal and national courts. However, a lack of uniformity between the law as applied by the boards of appeal and national courts could, in theory, bring to the fore a point of law of fundamental importance.

In T 2477/12 the board held that the application of the same legal principles and criteria may lead to different results in different cases. This is a consequence of the specific facts of each individual case and not, however, an indication of a contradictory interpretation or an inconsistent application of the law.

In G 1/12 (OJ 2014, A114), the Enlarged Board considered the requirement of non-uniform application of the law to be fulfilled because some decisions allowed deficiencies in the appellant's name to be remedied under R. 101(2) EPC, whereas in other decisions on analogous situations the boards applied R. 139 EPC. A minority of the members of the Enlarged Board were of the opinion that this merely demonstrated that, as long as the removal of the deficiency did not lead to a change of the appellant's true identity, both procedures were available according to consistent case law.