Felix paid €387 extra — for a “free” smartphone.

A 24-month lock-in, a price hike buried in spam, throttling on “fair use”, silent auto-renewal. SignGuard spots the traps in your Handyvertrag (German mobile phone contract) in 60 seconds — before they cost you.

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60 sec · free · iOS & Android · no credit card

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SignGuard in three simple steps

From upload to clause analysis — no lawyer appointment, no hours spent reading the TKG (German Telecommunications Act).

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Contract, terms, tariff confirmation — as a PDF or photo

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AI checks the clauses

Lock-ins, price hikes, throttling — in 60 sec.

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Traffic-light report with TKG references

Every critical clause with the exact section + € impact

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Handyvertrag.pdf

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4 classic German mobile contract traps

📊 4 in 10 price-increase emails are formally contestable (vzbv 2024)

24-month lock-in with hardware

up to€250

per year in subsidy markup

The “free” smartphone is paid off through your base fee — 30–50% above market price (§ 56 TKG).

Price hike in the fine print

up to€120

per year in extra costs

The mandatory notice of your special termination right is missing or buried. You have 3 months from receipt (§ 57 TKG).

Throttling despite a “flat rate”

up to€180

per year in forced upgrades

Drosselung (throttling) down to 64 kbit/s once you hit the data cap. If the minimum bandwidth is undercut, you can claim a price reduction (§ 57 TKG).

Silent auto-renewal

up to€200

per year of lock-in

Since 12/2021: renewal only for an indefinite term, cancellable monthly. A “12-month renewal” clause is void (§ 56(3) TKG).

High risk found? The Lawyer Check takes over.

If the analysis flags a high risk, you can forward your contract plus a case summary to an independent German lawyer (Rechtsanwalt) in one tap — a referral through the advocado partner network. The initial assessment is free and non-binding; after that, you decide freely on a fixed-fee basis. How the Lawyer Check works →

★★★★★

“I had a 40 GB plan for €39.99. After 18 GB, that was it — 16 kbit/s, I couldn't even load WhatsApp voice messages. The provider said: 'It's in the terms.' SignGuard checked the contract in 90 seconds and showed the guaranteed minimum bandwidth was persistently undercut — § 57 TKG. Four months of fees back (€160), plus extraordinary termination.”

Sarah K.

Trainee teacher, 29, Leipzig

Anonymized case study · sample calculation: €39.99 × 4 months refunded · How to cancel a German mobile contract — step-by-step guide (German)

German mobile contract tools in 2026: check, compare, cancel

For German mobile contracts there are three kinds of tools: tariff comparison (find a new plan), cancellation services (send the notice), and contract checking (review the clauses you already signed). SignGuard is the clause checker.

Tool	Category	What it does	Price
SignGuard (iOS app)	Clause check	Checks minimum term, throttling, price increases, auto-renewal — 60 sec, with § TKG references	3 free, then from €4.99/month
Aboalarm / Volders	Cancellation	Sends cancellation notices for mobile plans & subscriptions	per cancellation
Verivox / CHECK24	Tariff comparison	Compares new mobile plans, brokers the switch	free (commission-based)
Verbraucherzentrale (consumer advice center)	Advice	In-person advice in disputes with your provider	approx. €30–90

Rule of thumb: For a cheaper plan, use Verivox/CHECK24; to cancel fast, use Aboalarm. To find out whether your existing mobile contract has fair clauses (throttling, price increases, renewal) — and whether the TKG reform lets you out earlier than you think — use SignGuard (3 free checks).

Common questions about German mobile contracts

Which app shows hidden costs in a German mobile phone contract?

SignGuard uses AI to check your German mobile contract for hidden cost traps in 60 seconds: automatic price increases, throttling despite an advertised flat rate, paid add-on services, silent auto-renewal, and overlong minimum terms. You upload the contract as a photo or PDF and get a clause traffic light with statutory references (§ 56/§ 57 TKG on cancellation and price changes). Unlike tariff comparison portals (Verivox, CHECK24), which compare new plans, SignGuard checks the clauses of the contract you already have. 3 free checks, GDPR-compliant, EU-based servers.

How do I cancel my German mobile contract correctly?

Since December 2021, every provider must offer a cancellation button on its website (§ 312k BGB — German Civil Code). Text form is enough — an email counts. After the initial term, the notice period is 1 month instead of the previous 3. Step-by-step guide: How to cancel a German mobile contract, with a template letter (German) → Hit by a shock roaming bill? Roaming in 2026: the 7 cost traps — and how to avoid them (German) →

Price increase — what is my provider allowed to do?

Price increases are allowed, but the provider must inform you clearly and in good time and point out your special termination right (§ 57(1) TKG). You then have 3 months from receipt to cancel without notice. If that notice is missing, the increase is often contestable — according to the German consumer association vzbv, that applies to 4 in 10 price-increase emails.

Throttling — what speed does my provider owe me?

Since the TKMoG reform (December 2021), every contract must state three values: minimum, normal, and maximum bandwidth. If the minimum bandwidth is persistently undercut, you are entitled to a price reduction or special termination (§ 57(4) TKG). For proof, use the official BNetzA broadband measurement tool.

Auto-renewal — is it still allowed in Germany?

Contracts signed from December 2021 onwards may only renew for an indefinite period with a monthly cancellation right. Clauses with a “12-month renewal” are void in new contracts (§ 56(3) TKG). Watch out if you're a long-standing customer: providers still rely on their old terms.

Can I terminate early when I move within Germany?

If the provider cannot deliver the promised service in comparable quality at your new address, you can cancel with one month's notice (§ 60 TKG). Moving alone is not enough — only reduced availability at the new address counts.

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Important legal notes

Sample calculations: All € figures (€387 hero story, €250/year lock-in, €120/year price hike, €180/year throttling, €200/year renewal, €160 in the testimonial) are illustrative examples based on typical German mobile plans (premium all-net tariffs at €40–60/month, hardware subsidies via a 24-month lock-in). Actual losses vary widely by plan, provider, and contract term.

Legal basis: The cited provisions (§ 56(1) + (3) TKG initial term + renewal, § 57(1) + (4) TKG price increases + minimum bandwidth, § 60 TKG special termination on moving, § 312k BGB cancellation button) reflect the German Telecommunications Act (TKG) as of 2026 and the TKMoG of June 23, 2021. Sources for consumer-protection statistics: Verbraucherzentralen (consumer advice centers) NRW/Bavaria/Hamburg 2024, BNetzA annual report 2024.

Case study: The case shown (“Sarah K., trainee teacher, Leipzig”) is an anonymized example illustrating a typical throttling scenario. Personal details are fictional.

No legal advice: SignGuard is a digital contract manager with AI-powered clause analysis. The app is for information purposes and does not replace advice from a lawyer. In a dispute over a price increase, throttling, or special termination, contact a consumer advice center (Verbraucherzentrale) or a lawyer specializing in telecommunications law. And if the analysis flags a high risk: the Lawyer Check connects you with a free initial assessment by an independent German lawyer through the advocado partner network, right from the app.