At a glance
- Email marketing only with consent
- Exception: existing customers (Section 7(3) UWG)
- Document telephone consent for five years
Unsolicited marketing by email or phone is one of the most frequent causes of warning letters – from competitors and from recipients themselves. Fines from the Federal Network Agency and data protection authorities may follow.
| Channel | Consumers | Businesses |
|---|---|---|
| email, text, messenger | prior express consent | prior express consent |
| telephone call | prior express consent | presumed consent sufficient |
| automated calls, fax | prior express consent | prior express consent |
| postal mail | permitted unless objected | permitted unless objected |
“Advertising” is understood broadly and includes satisfaction surveys, birthday vouchers and ads in order confirmations.
Existing customer exception (Section 7(3) UWG)
Email marketing without consent is permitted only if all conditions are met: the address was obtained in connection with a sale, the advertising concerns the trader’s own similar products, the customer has not objected, and the customer is clearly informed – at collection and in every email – that they can object at any time. According to the CJEU, no additional legal basis under Art. 6 GDPR is needed in that case, and registration for an online service may qualify as a “sale” (CJEU, 13 November 2025, C-654/23, Inteligo Media).
Case examples
A directory publisher calls trade businesses to sell listings, relying on presumed consent. That is not enough without a concrete interest of the business in this very call; the calls are unlawful harassment.
A news site sends registered users a free newsletter without separate consent. The CJEU (13 Nov 2025, C-654/23) held this may qualify as existing-customer marketing, provided a clear opt-out is offered at registration and in every mail.
Feedback e-mails after a purchase serve customer retention and therefore count as advertising. Without consent they are only lawful under the existing-customer exemption, including the opt-out notice.
Obtaining consent
Double opt-in (the confirmation email must not contain advertising), specific and informed consent per channel and company, no pre-ticked boxes, and proof of consent. For telephone marketing to consumers, consent must be documented and retained for five years (Section 7a UWG); breaches are subject to fines (Section 20 UWG).
