Contracts Cannot Be Voided under Both National Law and CISG

Aug 27, 2026 Benn-Ibler Rechtsanwälte

In the case at hand, the Austrian Supreme Court (Oberster Gerichtshof, hereinafter OGH) was required to consider, among other issues, whether a contract subject to the UN Convention on Contracts for the International Sale of Goods (CISG) may be rescinded on the basis of mistake under national law, in addition to the remedies expressly provided by the CISG.

Telescopic grandstand system suitability

The case involved a contractual agreement for the provision of a mobile telescopic grandstand system between a Slovenian manufacturer and an Austrian trade fair organisation. The intention was to utilise the new grandstand system within a municipal hall, replacing the previous system to facilitate more efficient assembly and dismantling processes. Nevertheless, owing to considerable floor irregularities within the municipal hall, the newly implemented system did not result in a notable decrease in the time needed for set-up and dismantling. 

The claimant requested payment of the purchase price. The defendant later challenged the contract, citing a mistake regarding the suitability of the grandstand system for efficient and flexible deployment within the specific municipal hall.

Exclusive applicability of the CISG

Accordingly, the OGH was required to assess whether a challenge based on mistake was permissible in this particular instance. It was concluded that the CISG does not address every potential issue arising from contracts of sale. The CISG primarily sets out the rights and obligations of buyers and sellers, with only limited regulation concerning contract formation. 

The CISG prevails over domestic legislation when it addresses a particular issue. Recourse to national law is appropriate only in situations where the CISG lacks applicable provisions pertaining to the subject matter.

After a comprehensive examination of prevailing legal interpretations, the OGH concluded that national provisions concerning avoidance on the grounds of mistake cannot be applied alongside the remedies provided under the CISG when disputes arise regarding the nature of the object of sale.

Consequences and considerations arising from the decision

In this case, the ruling specified that, under Austrian law (Sections 871 et seq. of the General Civil Code, ABGB), the defendant was precluded from citing a commercial error regarding the characteristics of the grandstand system. 

OGH 6 Ob 100/25m (30 June 2026)