mail fraud: OLG Cologne ruling protects creditors from altered bank details

mail fraud: the facts of the case

mail fraud via manipulated mail is a growing concern, as shown by the OLG Cologne ruling. the case revolved around a compulsory portion claim. the parties, represented by their lawyers, had reached an out-of-court settlement for a severance payment of 30,000 euros. the lawyers exchanged the written settlement by mail. however, something unexpected happened in transit: an unknown third party altered the second page of the contract and replaced the claimant’s lawyer’s correct bank details with those of a fraudster.

the lawyer for the defendant (the party obliged to pay) signed the manipulated contract and sent it back without noticing the change. he then duly transferred the 30,000 euros – but to the wrong account. the money was lost. the claimant, who never received her money, subsequently sued the defendant again for payment.

the Cologne Regional Court initially dismissed the claim. it argued that the claimant’s lawyer should have checked the returned, signed contract. by failing to do so, she had negligently enabled the fraud and must bear the consequence that the payment to the wrong account could be considered as performance.

the turn: OLG Cologne rules in favor of the claimant

1. no attribution of the manipulated declaration: the court clarified that the manipulated bank details cannot be attributed to the claimant. the lawyer had correctly submitted her declaration (the signed contract offer) by regular mail. that a third party altered it during transit does not fall within her sphere of risk. she was entitled to rely on the mail arriving safely.
2. no duty to re‑examine: the OLG rejected imposing on the lawyer a duty to scrutinize the returned, defendant‑signed contract again for manipulations. such a duty would unduly burden legal transactions. who would expect a seemingly binding, mailed contract to be tampered with?
3. no obligation to use the beA: the defendant argued that the claimant’s lawyer should have used the secure “special electronic lawyer mailbox” (beA). the OLG denied such a duty in out‑of‑court written correspondence. choosing regular mail was lawful and common.
4. the contract is valid – but for the correct account: the decisive question was whether a contract had come into existence at all. yes, said the OLG. the agreement had essentially been reached: amount of payment, waiver of further claims. only the bank details were not mutually agreed. since this is not an essential contractual element, the contract remains valid. however, payment should have been made to the claimant’s lawyer, not to a third party. because this did not happen, the claimant’s claim has not been extinguished.

practical lessons from the ruling

• risk allocation: the risk of tampering in transit basically falls on the debtor. before making a payment, he should verify the bank details via a second, independent channel (e.g., by phone) in critical cases. creditors should stay alert to possible fraud via mail.
• sensitivity to bank data: the judgment reminds us of the immense importance of bank details. even the slightest change should raise alarm. legal practitioners recommend verifying bank details to avoid fraud.
• advantage of electronic communication: although no obligation exists, the case highlights the benefits of the beA. electronically signed and encrypted documents are far more tamper‑proof than paper mail.
• for legal practice: the judgment strengthens the reliability of declarations of intent. one does not constantly have to expect that sent documents are tampered with.

outlook: the appeal is allowed

the OLG Cologne has allowed the appeal to the federal court of justice (BGH). it considers the question of whether § 120 BGB (which governs incorrect transmission) also applies to conscious manipulations by third parties as unsettled at the highest court level and of fundamental importance. therefore it remains exciting to see whether the BGH will uphold the Cologne line.

conclusion: the OLG Cologne has sent a clear signal: creditors do not have to bear every conceivable fraud risk. anyone wishing to act in accordance with the contract also shares responsibility for ensuring the correctness of the payment recipient’s data. anyone who wants to pursue such a case through all instances bears a real cost risk – comparable to litigation funding in dismissal protection proceedings. the federal court of justice confirmed this decision on 08.10.2025 (case IV ZR 161/24) in substance and thus created legal certainty in an era where fraud schemes are becoming ever more sophisticated.

Note: This article is for general information purposes only and does not replace individual legal advice. For a free initial assessment of whether litigation funding may be an option for your case, you can contact RechtStark.