At a glance
- Secure dated evidence
- Prove the competitive relationship
- Warning letter under Section 13 UWG, then interim relief if needed
Unfair advertising gives a competitor an edge that honest businesses pay for. The UWG gives competitors the means to remove that edge quickly. What counts is evidence, speed and a warning letter that meets the formal requirements.
1. Secure evidence
Screenshots with visible URL and time, screen recordings, test purchases, neutral archiving, proof of your competitive relationship – and the date you first became aware, which starts limitation and urgency periods.
2. Check standing
Only those who sell goods or services to a not insignificant extent and not just occasionally are competitors (Section 8(3) no. 1 UWG). Courts examine this more strictly since 2020.
3. Choose the strategy
| Route | Advantage | Disadvantage |
|---|---|---|
| warning letter | cost reimbursement, out-of-court solution | opponent may file a protective letter |
| injunction without prior warning | surprise, quick order | cost risk if the opponent acknowledges immediately |
| “drawer injunction”: obtain order first, then send warning | pressure and control | warning costs not recoverable |
4. The warning letter and next steps
It must contain the details required by Section 13(2) UWG, describe the infringement precisely, set an appropriate deadline and enclose a proportionate declaration. Excessive demands can make the warning abusive. If no adequate declaration is received, we apply for a preliminary injunction within the urgency period. If a declaration is given, compliance must be monitored.
Case examples
Before sending a warning letter we secure screenshots with date and URL and make a test purchase. Content tends to change quickly once a warning arrives.
A manufacturer is being denigrated to dealers by circular letters. Because further letters are imminent, we apply for an injunction without prior warning and accept the cost risk.
Following the BGH (10 April 2025, I ZR 80/24), costs are recoverable only in the amount stated in the warning letter. We always state them precisely.
Cost risk
If the warning is justified, the opponent bears the costs. If standing is lacking or the claim is unfounded, you risk your own costs and a counterclaim (Section 13(5) UWG). We assess and quantify the risk upfront.
