Suspected Algorithm Bias for Tenants in Germany

As a tenant in Germany you may sometimes suspect that automated decisions or algorithms affect your housing situation — for example in credit checks, applicant selection or utility billing. This practical guide explains how to recognise algorithm bias, which evidence matters and how to document systematically. You will get clear steps for photos, logs, e‑mails and a practical sample letter to inform the landlord or prepare a complaint. We also show when a written filing with the local court or legal advice is sensible and which legal bases (BGB, ZPO) play a role. The language remains accessible so you can assert your rights as a tenant with confidence.

What is algorithm bias?

Algorithm bias means that automated procedures systematically disadvantage certain people. For tenants this can mean: automatic credit assessments reject applications without clear reason, automatic analysis tools misattribute consumption data or billing software calculates incorrectly. Bias is not always intentional; often incomplete data or faulty training sets play a role.

When should tenants in Germany be suspicious?

• Unexplained deviations in bills or sudden increases in requested payments.
• Repeated rejections of housing applications without a verifiable reason.
• Missing or contradictory evidence, logs or e‑mail correspondences that could explain decisions.
• Technical errors in heating or water data leading to incorrect consumption bills.

How to document: Collect evidence and sample letter

Collect all relevant evidence systematically: photos, screenshots, invoices, e‑mails and timestamps. Note date, time and exactly what was unusual. Create a simple folder structure (e.g. "Date - Topic") and back up digital files to the cloud or by e‑mail to yourself.

1. Save photos and screenshots of errors, bills or faulty listings immediately.
2. Save e‑mails, confirmations and automated messages as PDFs and note timestamps.
3. Document deadlines and appointments: date of the error, the date of communication and any set deadlines.
4. Sample letter: write briefly and specifically, request the basis of the decision or correction and state a deadline and possible next steps.

Sample letter (short template)

Dear Landlord,

On [date] I noticed the following inconsistency: [brief description]. Please send me by [date, e.g. 14 days] the basis for this decision (e.g. log files, calculations, verification protocols) or correct the billing. If no satisfactory response is given, I reserve the right to take legal steps.

Sincerely,
[Your name]

Forms and when they apply

In many cases there is no standard official form for a complaint letter, but there are standard procedural routes if a legal dispute arises. Important forms and occasions:

• Termination letter (tenant): used when you wish to terminate the tenancy properly; it should include date, termination reason (if relevant) and signature.
• Filing a civil claim at the local court: for serious disputes a claim is often necessary; the statement of claim follows formal requirements of the ZPO^[2].
• Objection or complaint to the billing software provider: request disclosure of the underlying data in writing.

Legal steps and courts

If an amicable solution fails, the competent courts are usually the local court (Amtsgericht) for tenancy disputes; in higher instances the regional court and possibly the Federal Court of Justice.^[3] Statutory duties of the landlord on defect remedy and retention are regulated in §§ 535–580a BGB; these sections are often decisive if an automated decision affects habitability or payment obligations.^[1]

FAQ

How do I prove that an algorithm is faulty?

Document deviations systematically, collect comparison data, screenshots, e‑mails and timestamps; try to identify patterns across multiple cases.

Can I force my landlord to disclose data?

You cannot directly force disclosure without a court decision; you can request information in writing and, if necessary, apply to the local court for disclosure.

What deadlines do I need to observe?

Act quickly: set a concrete deadline in the sample letter (commonly 14 days) and check statutory limitation periods if payments are affected.

How-To

1. Secure all relevant evidence immediately and back up digital copies.
2. Note deadlines and set a reasonable response period in the sample letter.
3. Send the sample letter by registered mail or by e‑mail with read receipt.
4. If no resolution is reached, consider court action at the local court or seek legal advice.

Help & Support

• Federal Ministry of Justice and Consumer Protection (BMJ)
• Gesetze im Internet (BGB, ZPO)
• Federal Court of Justice (BGH)

1. [1] Bürgerliches Gesetzbuch (BGB) §§ 535–580a – gesetze-im-internet.de
2. [2] Zivilprozessordnung (ZPO) – gesetze-im-internet.de
3. [3] Federal Court of Justice (BGH) – bundesgerichtshof.de