In its judgment the BGH confirmed the decision of the court below and made clear that the clause at issue was subject to review of its content and that it would fall at his hurdle due to breach of the principle of transparency in § 307 (1), 2nd sentence BGB, given context-specific expression in § 651a (4), 1st sentence. Therefore, the travel organiser had to cease using these clauses and clauses of similar content in contracts with consumers.
The clause at issue has, according to the BGH, a statute-extending character and is thereby subject to review of its content according to § 307 (1) BGB. This without prejudice to the exclusive reference in § 651a (4), 3rd sentence BGB to § 309 No. 1 BGB. § 651 BGB does not prescribe a certain form for a possible price increase clause and therefore does not give the travel organiser any discretion for the formulation of price increase clauses. The price amendment clause at issue fills in this framework and is thus to be regarded as a clause extending dispositive law.
It follows from the clear wording of § 651a (4), 1st sentence BGB, which transposed Art. 4 (4) Package Travel Directive 90/314/EEC verbatim in this respect, that the exact details for the calculation of a price increase must be contained in the contract. Other means of conveying this information, e.g. in information sent following conclusion of contract, is not sufficient.
According to the view of the BGH, the clause at issue breaches the principle of transparency above all for two reasons. Firstly, it does not contain any clear limitation to actual cost increases following conclusion of contract, moreover it gives no reference points in time for the determination of the cost increases to be passed on to the customer. Due to the ambiguity of the clause, it remains unclear whether all cost increases for the respondent since formulation of the price or publishing of the brochure are to be incorporated or only those costs following conclusion of the contract. Looking at both clauses together, the clause makes it possible for the respondent to take at will not only those cost increases which arose or were foreseeable following conclusion of contract but also those which arose prior to conclusion of contract as the basis for the price change. Secondly, the clause determines that price changes are possible to the extent that they affect the respective price per head or per seat. This formulation leaves the respondent the choice of passing on cost increases to its contractual partner either on the basis “per head” or “per seat”. There are no concrete details as to cost factors, apportionment or calculation methods. Thus, at conclusion of contract the traveller is unable to identify from the clause the method by which price changes will be applied to him.
The Package Travel Directive however requires that the exact details of the calculation methods to be applied for price increases are contained in the contract. Travel organisers are obliged to observe the conditions of Art. 4 (4) Package Travel Directive and thereby also § 651a (4),1st sentence BGB. Art. 4(4) of the directive accordingly contains a principle of transparency already recognised in the case law to § 9 AGBG (Allgemeine Geschätfsbedingungsgesetz – Standard Contract Terms Act) (now § 307 BGB), which recognised in law an essential need of protection of the contractual partner of a travel organiser to be able to also carry out his own calculations to examine the justification for a price increase.
As this clause leaves unclear, which type of cost increases constitute the basis for requiring an increased travel price, it is ambiguous, as a consequence of which it is subject to customer friendly interpretation [contra preferentem rule].
The issue of whether the term “flight duties” in the clause is ambiguous was not relevant to the decision. Due to the clarity of the situation, the BGH expressly declined to make a preliminary reference to the ECJ on the interpretation of the Package Travel Directive.