Meta Tech ProviderCompared · Germany
Voice AI platforms compared, for German businesses
For a German business the choice comes down to five checks: whether you can keep your number, whether the agent speaks German and Turkish and handles Sie and du, how outbound calls sit with section 7 of the Unfair Competition Act, what recording and professional secrecy allow, and whether WhatsApp is part of the same agent. This page puts ThinnestAI beside three developer platforms on those checks, with the sources and the date we read them.
What to check
Five things to check before you choose, in Germany.
Put the last column to every supplier you are weighing, ThinnestAI included.
| Check | Why it matters in Germany | ThinnestAI | Ask any supplier |
|---|---|---|---|
| A number you can keep | A trade or practice in Germany is usually known by one local number, on the van, the sign and the listings, and the owner is often on a job when it rings. | Connect the number from your own Twilio, Telnyx or Plivo account, or forward calls to one; forwarding after hours is the easiest first step. We don't sell German numbers. On Telnyx, outbound calls go only to the countries switched on in your voice profile, so add Germany before you call out. | Can the agent answer my existing number outside opening hours, and what happens to that number if I leave? |
| German, Sie and du | Callers expect to be addressed correctly, and some ring in Turkish, Polish or Russian rather than German. | German and Turkish are among the 50 voice languages, and chat covers German, English, Turkish, Polish and Russian. We claim German, not a regional variety, so we promise nothing for an Austrian or Swiss accent or for Bavarian or Swabian. Sie or du is set in the instructions you write. | Can I set Sie or du in the instructions, and can I hear the German voice before I commit? |
| Outbound calling rules | Under section 7(2) of the Unfair Competition Act (UWG), an advertising call to a consumer needs prior express consent, one to another business at least presumed consent, and an automatic calling machine needs prior express consent in every case. Section 7a asks you to document a consumer's consent (read 25 October 2026). | You set calling hours per campaign on the called person's clock and keep your own do-not-contact list. The agent does not collect or check consent and screens against no register. We could not verify whether a voice agent counts as an automatic calling machine, so plan on the stricter view. | Where is consent recorded for each call, and who keeps the proof? |
| Recording and professional secrecy | Section 201 of the Criminal Code punishes recording another person's non-public spoken word without authorisation. Section 203 punishes doctors, dentists, lawyers, tax advisers and other listed professions who disclose a secret entrusted to them. | Recording is a per-agent switch that stays off until you turn it on, and the opening line is yours to write, so it can say the call is recorded. For a practice or a law firm we have not verified whether our terms carry the secrecy obligation section 203 asks for, so ask for it in writing; it may rule the product out. We make no claim that the product meets any local law. | Will you bind yourselves to secrecy in writing, and is recording off by default? |
| WhatsApp and billing | The Bundesnetzagentur and the UWG require prior express consent for advertising by electronic mail, and the IHK guidance we read treats SMS and WhatsApp as covered. We found no court ruling on WhatsApp itself. | One agent answers the phone, WhatsApp and website chat, with a shared inbox where your team can take over. Whether your messages count as advertising is for your adviser. Billing is in US dollars by card; there is no euro billing. | Is WhatsApp handled by the same agent and the same inbox, and which currency will the invoice be in? |
Side by side
ThinnestAI and three developer platforms, for Germany.
Cells about other companies come from their own documentation, read on 25 October 2026.
| ThinnestAI | Vapi | Retell AI | Bland AI | |
|---|---|---|---|---|
| What it is | A managed agent with a shared inbox, campaigns and a call log | A developer platform that connects speech, language-model, voice and telephony providers | A developer-first voice agent platform | Voice agents with Pathways branching flows |
| Channels | Phone, WhatsApp, website chat, Telegram: one agent, one memory | Voice-focused | Voice and chat | Voice and SMS |
| Price shape | Flat per-minute rate — see pricing | A platform fee per minute plus the providers you choose | Priced per component | Bundled per connected minute |
| Phone numbers in Germany | Bring a number you own on Twilio, Telnyx or Plivo; we don't sell German numbers | Free numbers use US area codes; outbound calls and other countries use a number imported from a carrier such as Twilio or Telnyx | Sells numbers in the US and Canada only; other countries use your own provider | Sells numbers in the US and Canada; for other countries its documentation says to contact support |
| Languages for Germany | Voice in German, Turkish and English (American, British and others), plus Italian, Spanish, French and more; chat replies in 37 languages, German, English and Turkish among them | Depends on the speech and voice providers you choose | Depends on the voice and speech providers; the dashboard greys out unsupported choices | Its site states 40+ languages; check yours on a test call |
| Agent setup | Tabbed settings, no flow canvas | Visual Workflows builder | Conversation Flow builder | Pathways branching flows |
| Shared inbox and human takeover | Yes | No | Not checked | Not checked |
| Billing | US dollars, by card | US dollars | US dollars | US dollars |
Read on 25 October 2026 from each company's own pages: Vapi (phone calling, multilingual); Retell AI (purchase a number, language); Bland AI (purchase a number, site). Products change; check each page before you decide. Prices are not compared here: ours are on the pricing page, and theirs are on theirs.
Other options
Other kinds of supplier in Germany.
Kinds of supplier, not companies. Each is the right call for someone.
A staffed telephone service
People answer in German, take a message and can judge a worried caller. It is the better call when every caller needs a person from the first word, as in many practices. It cannot take a hundred calls at once or work through a list of leads.
A cloud phone system with a menu
A hosted phone system from a German supplier gives you the number, opening-hours routing and voicemail in one place. It sends calls where you tell it. It does not understand a question, book a service visit or leave you a transcript.
Building on a developer platform
A team with developers can combine speech, language-model, voice and telephony providers into exactly the agent it needs, and decide for itself which parts to use. The price of that control is build time: you own the testing, the inbox and the billing for each part.
Plainly
Who should pick what.
ThinnestAI fits when
- You run a trade, workshop or property manager and miss calls while you are on a job; you want the address and urgency noted and a callback promised.
- You want German and Turkish voices, with Sie or du set in your own instructions, tested by a native speaker before any customer hears it.
- You want the phone and WhatsApp handled by one agent with a shared inbox, and you are a small team that needs a managed product rather than a build.
Something else fits better when
- You are a doctor, dentist, lawyer or tax adviser bound by section 203, and your contract must carry a secrecy obligation we have not verified. A staffed service bound in writing is the safer call.
- You plan to cold-call consumers at scale. German law needs documented prior express consent for each, and the agent does not collect or check consent, so you need a tool that does, or your own staff.
- Your buyer asks for a security certificate we do not claim, or your engineers want to build their own call flows. We claim no certification and have no flow builder; a developer platform gives that control.
Questions
Common questions.
Can I keep my German phone number?
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Do the other platforms sell German numbers?
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Can the agent make advertising calls in Germany?
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Can a doctor or law firm use it?
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Test it on your own calls in Germany.
Create an agent, give it your own information, and ring it from your browser before you connect a number. Then put the same test to the others.