Like Odysseus – Between Scylla and Charybdis

In the twelfth book of the Odyssey, Odysseus must steer his ship through a narrow strait: on one side the six-headed monster Scylla lurks in the rock, on the other the whirlpool Charybdis drags ships into the deep. Avoid one danger and you drift toward the other. Anyone drafting standard terms with notice-of-defects periods knows this narrow passage — only here the two cliffs are called § 377 HGB and Art. 39 CISG. A judgment of the Higher Regional Court of Cologne (OLG Köln) from early 2025 shows vividly how little water lies between them.

The starting point: the OLG Köln on avoiding an international sales contract

A German procurement body had bought FFP2 masks through a so-called open-house procedure; the latest delivery date was 30 April 2020. The suppliers — based in China and the Czech Republic — delivered in part late. The buyer relied on a standard-form fixed-date clause (“If the latest delivery date is not met, the parties’ mutual obligations lapse …”) and declared rescission months later. The suppliers sued for the purchase price.

The OLG Köln found for the suppliers (judgments of 9 January 2025 – 8 U 46/23 – and 6 February 2025 – 8 U 38/23). Three points matter for contract drafting:

• A choice of law does not exclude the CISG. The clause “law of the Federal Republic of Germany, excluding the conflict-of-laws rules of private international law” does not opt out of the CISG — because the UN Sales Law is part of German law. Even arguing on the basis of the BGB/HGB does not show an intention to exclude it (Art. 6 CISG); it may be due to lawyerly caution or to error.
• The yardstick for the fairness review is the statutory model of the CISG. An automatic avoidance without a declaration (Art. 26 CISG) and without a fundamental breach or a Nachfrist (Art. 49 CISG) conflicts with that model and unreasonably disadvantages the suppliers — § 307 (2) no. 1 BGB. That provision applies because the CISG does not govern the fairness review of standard terms and the parties had chosen German law.
• The notice of defects was too late. Referring to an average period for notice under Art. 39 CISG of about one month, the court rejected the notice given only after six weeks as out of time.

It is this last point that opens the strait we are concerned with here.

Charybdis: the CISG will not tolerate a notice period that is too short

Under Art. 39 CISG the buyer loses its remedies if it does not give notice of a defect within a reasonable period. German case law orients itself on a benchmark of roughly one month (the much-cited “noble month”) — a comparatively generous period that a buyer genuinely needs in a cross-border transaction.

A user that tries to cut this period down drastically in its standard terms — say, to a few days — sails into the whirlpool: because § 307 BGB remains applicable where German law is chosen, the clause is measured against the statutory model of the CISG. A notice period clearly below the reasonable period of Art. 39 CISG departs from that model and is, in case of doubt, void. In short: under the UN Sales Law the notice period must not be too short.

Scylla: the HGB will not tolerate a notice period that is too long

In a purely domestic commercial sale the opposite applies. § 377 HGB requires the buyer to inspect the goods without undue delay and to give notice of defects without undue delay; otherwise the goods are deemed approved. The statutory model is therefore prompt clarification in the interest of legal certainty — not a generous time buffer.

Here, too, the model is the yardstick for the fairness review: the Federal Court of Justice (BGH) measures standard-form arrangements on the duty to inspect and give notice against § 307 (2) no. 1 BGB in conjunction with § 377 HGB. Clauses that shift the defect risk one-sidedly, contrary to that model, are void (BGH, judgment of 6 December 2017 – VIII ZR 246/16; on the interest-based determination of the duty, BGH, judgment of 24 February 2016 – VIII ZR 38/15). The corridor of permissible drafting is narrow — and it points in the opposite direction to the CISG: in a commercial sale the notice period must not be too long.

“The yardstick of the fairness review is the statutory model — for the commercial sale § 377 HGB, for the cross-border sale the UN Sales Law.”

The adviser’s dilemma

Here the trap closes. It is the same provision — § 307 (2) no. 1 BGB — that decides whether the notice-period clause is valid. But it measures that clause against two opposing models, depending on whether the HGB or the CISG applies to the contract. A single notice-period clause meant for all cases therefore risks failing on one side every time:

• drafted tightly (HGB-friendly), it collides with Art. 39 CISG in the export business;
• drafted generously (CISG-safe), it sits uneasily with § 377 HGB in the domestic business.

And there is the preliminary question the OLG Köln highlights so clearly: whether the CISG applies at all is not decided by a blanket choice of “German law”, but by the conditions of Art. 1 CISG. Anyone who genuinely wants to exclude the UN Sales Law must do so expressly. The adviser must therefore review a notice-period clause twice — against the model of the CISG and against the model of the HGB. In practice, that means choosing a safe course between the cliffs:

• Separate the regimes: distinct sets of standard terms for purely domestic sales (HGB) and for cross-border sales (CISG) instead of one “universal clause”.
• Stagger the notice period by regime: tie the period to the applicable law rather than fixing a rigid number of days for all cases.
• Make the choice of law deliberately and expressly: if the CISG is not to apply, exclude it clearly — not merely by agreeing on “German law”.
• Do not formulaically upgrade fixed dates: mere failure to meet a delivery date is, under the UN Sales Law, generally not a fundamental breach and cannot be turned into one by an ipso-facto clause.

Conclusion

The OLG Köln is a reminder that the fairness review leads no national life of its own: once German law is chosen, § 307 BGB tests the clause against the model of whichever sales regime applies. For the notice period this means a genuine navigation problem — too short fails under the CISG, too long under the HGB. Those who know both cliffs can steer through; those who watch only one run aground.

It is therefore worth examining every notice-of-defects clause before a dispute arises — ideally separately for the domestic and the export business. We are happy to support you in drafting or reviewing your purchasing and sales terms.

This article reflects the state of the sources reviewed and serves general information purposes; it does not constitute legal advice in an individual case. German law is decisive; for foreign law an external adviser may be consulted.