Consent and double opt-in: German law and the BGH quoted

Last reviewed: 2 November 2026

Translated from German; if the versions differ, the German version applies.

Not legal advice: Legal content on this page appears only as verbatim quotations from statutes, court rulings or authority papers, with their source; quotations from German texts are our working translations. We do not assess them ourselves, and no lawyer has reviewed this page. It is no substitute for legal advice in your individual case.

What the laws say

Quotations from German laws, court rulings and authority papers are our working translations; only the German wording is authoritative (see the German version of this page). GDPR quotations follow the official English text.

Section 7(2) no. 2 of the UWG (the German Act against Unfair Competition, Gesetz gegen den unlauteren Wettbewerb) reads:

“An unacceptable nuisance is always to be assumed […] in the case of advertising using an automatic calling machine, a fax machine or electronic mail without the prior express consent of the addressee” (our translation) — Section 7(2) no. 2 UWG

The EU General Data Protection Regulation (GDPR) lists consent as one of the conditions under which processing is lawful: “the data subject has given consent to the processing of his or her personal data for one or more specific purposes” (Art. 6(1)(a) GDPR). On proof and withdrawal it says:

“Where processing is based on consent, the controller shall be able to demonstrate that the data subject has consented to processing of his or her personal data.” — Art. 7(1) GDPR

“The data subject shall have the right to withdraw his or her consent at any time. […] It shall be as easy to withdraw as to give consent.” — Art. 7(3) GDPR

Existing customers: Section 7(3) UWG

For email advertising to customers, Section 7(3) UWG contains a rule of its own:

“By way of derogation from subsection 2 number 2, an unacceptable nuisance is not to be assumed in the case of advertising using electronic mail if

a trader has obtained the customer’s electronic mail address from the customer in connection with the sale of goods or services,

the trader uses the address for direct marketing of its own similar goods or services,

the customer has not objected to the use, and

the customer is clearly and distinctly informed, when the address is collected and each time it is used, that they may object to the use at any time without incurring any costs other than the transmission costs at the basic rates.” (our translation)

— Section 7(3) UWG

More on the page Advertising to existing customers.

How double opt-in works technically

The person enters their email address in a sign-up form.
The sending platform sends a confirmation email with a confirmation link to that address.
Only when the person clicks the link does the system add the address to the mailing list.
The system logs the sign-up and the confirmation, for example with the time and the wording of the form.

The German Data Protection Conference (Datenschutzkonferenz, DSK), the body of the German data protection authorities, writes about this procedure in its guidance on direct marketing:

“For consent declared electronically, the double opt-in procedure is required to verify the declaration of intent of the data subject, whereby the BGH’s requirements of proof under the UWG (judgment of 10 February 2011 - I ZR 164/09) are to be taken into account in the logging. The procedure must be able to prove consent specifically with regard to the means of communication used for the advertising. Merely storing an IP address and claiming that consent was given from this IP address is not sufficient, according to the BGH’s case law on the UWG as well […]. Consent must be fully provable, including as regards its wording.” (our translation) — DSK guidance on direct marketing (February 2022), section 3.3, pp. 11–12

Sources

Orientierungshilfe der Aufsichtsbehörden zur Verarbeitung von personenbezogenen Daten für Zwecke der Direktwerbung unter Geltung der DSGVO (Februar 2022), Datenschutzkonferenz (DSK), Abschnitt 1.1 (Begriff der Werbung, S. 3), 1.3.2 (Praxisfälle Interessenabwägung, Profiling, S. 5), 1.4.1 (Bestandskunden, S. 6), 2.1 (Informationspflichten, S. 7–8), 3.1 (Gestaltung der Einwilligung, S. 10–11), 3.2 (Visitenkarten, S. 11), 3.3 (Double-Opt-In-Verfahren, S. 11–12), 3.4 (Koppelungsverbot, S. 12), 3.5 (Gültigkeitsdauer, S. 13), 3.6 (besondere Kategorien, S. 14), 3.7 (Widerruf, Nachweis, S. 14–15), 4.2 (Impressumsdaten, S. 15), 4.3 (Beipack-Werbung, S. 15), 5.1–5.4 (Werbewiderspruch, S. 17–20); 1.3.1 (Grundsätzliches zur Interessenabwägung, S. 4) (in German) (accessed on 2 November 2026)

What the BGH said about evidential value

On 10 February 2011, Germany’s Federal Court of Justice (Bundesgerichtshof, BGH) decided a case of telephone advertising to consumers (I ZR 164/09). Headnotes 2 to 5 read:

“2. To prove consent, it is necessary for the advertiser to document the specific declaration of consent of each individual consumer in full, which, in the case of a declaration of consent transmitted electronically, requires that it be stored and can be printed out at any time […]. 3. A confirmation email in the electronic double opt-in procedure neither proves the consumer’s consent to advertising calls nor, on its own, leads to an easing of the burden of proof in favour of the advertiser […]. 4. If, even after confirming their email address in the double opt-in procedure, the consumer wishes to claim that they did not give the consent to email advertising sent from this address, they bear the burden of presentation for this […]. 5. If the consumer can show that the confirmation transmitted by email did not come from them, the advertising mailing was anti-competitive even if the email address was obtained in the double opt-in procedure […].” (our translation)

— BGH, judgment of 10 February 2011, I ZR 164/09, headnotes 2–5

On email advertising, the reasons state:

“If an application to take part is received electronically, its sender can be asked by email to confirm their wish to take part. Once the requested confirmation has been received, it can be assumed that the application actually came from the email address given. If the consumer has confirmed by ticking a box in the entry form that they agree to receive advertising, it is in principle sufficiently documented that they expressly consented to email advertising to this email address […].” (our translation) — BGH, judgment of 10 February 2011, I ZR 164/09, para. 37

Pre-ticked boxes

Recital 32 of the GDPR contains this sentence:

“Silence, pre-ticked boxes or inactivity should not therefore constitute consent.” — Recital 32 GDPR

Whether a confirmation email in the double opt-in procedure may already contain advertising is not expressly answered by the law or by the sources quoted here.