Frequently Asked Questions – FAQ

Here you will find answers to the most frequently asked questions. Can't find the answer to your question? Feel free to contact us at support@fonio.ai

1. Phone Numbers & Telephone Numbers

Can I bring my own phone number or buy my own (German or Austrian) numbers?
Classic number porting is currently not possible, but we are already working on it. Many users simply forward their existing number to the AI number – this is sufficient for most use cases. You can integrate your number with Fonio via SIP. This way, you can bring your own number and use it in Fonio. You can find this feature under “Phone Numbers” at “Add Number” and “Create SIP Number”.

Can I use my own VOIP numbers?
Yes, you can use your own VOIP numbers via SIP. You can find this feature under “Phone Numbers” > “Add Number” > “Create SIP Number”.

Can I integrate local numbers into my telephone system (e.g., via SIP trunk)?
Yes, this feature is already in progress or partially available. You can then integrate Fonio as an extension in your telephone system – especially practical for larger companies.

What area code does a number I buy from you have?
The standard area code for a number from Germany is +49 30 (Berlin) and from Austria +43 720.

Do I need my own number, or is forwarding enough?
In most cases, call forwarding is completely sufficient. Your customers will still see your “real” number. Own numbers are only necessary in special cases – but you can add them anytime.

Can I buy a number with a freely selectable German area code?
Yes, you can request individual numbers. The area code corresponds to the location of your company.

Can I also use my own phone number?
Yes, you can connect your own phone number via SIP if that is an option for you.

Can I freely choose my phone number or use an already used number?
Yes, you can integrate an existing phone number via SIP if possible.

How do I get the caller's number when using a different main number?
To receive the caller's number, you should adjust the settings in your telephone system (e.g., 3CX) before forwarding the call to Fonio. This way, the original number is preserved.

How do I forward the caller's number via the API?
Pass the phone number as the variable "fromNumber" via the API.

Can I control the displayed number during forwarding?
Yes, in most telephone systems you can set whether the caller's number or the telephone system's number should be forwarded. Contact your telephone system provider if you need assistance.

Can I provide the AI with an internal phonebook with names and numbers to forward calls internally?
Yes, this is possible. You can use free call forwarding to forward calls internally.

Can I buy a Swiss number?
A Swiss number is currently only available on request; please fill out the form directly on the platform.

Do I need proof for purchased numbers?
Not for standard numbers, but for individual numbers with a desired area code, we require a commercial register excerpt.

Are there monthly fees for the phone number?
Yes, there is a monthly fee of €9 for the phone number.

Does the AI forward important calls to me if I forward my number to it by default?
Yes, that works. However, in some cases, a loop may occur where calls are continuously forwarded back and forth between the AI and your phone.

Important: If you experience forwarding loops, do not set up explicit call forwarding from the AI assistant's number back into your PBX system, as this will worsen the problem by creating the exact mechanism that causes the loop.

Where does the system get the mobile number if someone calls from a landline?
SMS is always sent to the calling number. However, you can set SMS to be forwarded to another specific number.

Can I connect Fonio as an extension to save forwarding costs?
Yes, you can connect Fonio via SIP if possible.

2. Call Forwarding & Assistants

Can the AI forward calls?
Yes! You can specify exactly in the prompt when and where to forward. In Tools → Forwarding you set the targets – the AI then takes over automatically.

Can I create multiple assistants?
Yes, you can create as many assistants as you like. Most use 1–3 assistants, but there is no limit. Creating assistants is free of charge.

Can I copy assistants and adjust the templates?
Yes, you are able to duplicate your assistants. In the overview of your assistants click on the three dots and choose "Duplicate".

How can I use the multilingual assistants?
To speak with multilingual assistants, you can directly ask during the conversation to switch languages (e.g., “Can we continue in English now?”). Make sure the assistant supports language switching.

What happens to the recording if the caller does not want their call recorded?
If the caller does not want the call recorded, you can forward them to a designated number. In this case, the recording ends when the forwarding starts.

Can I set up direct call forwarding?
Unfortunately, this is currently not possible, but such a feature is planned and will be available soon.

Are the multilingual assistants Anna, Sophie, Ben, and Brian automatically multilingual?
No, they are not automatically multilingual. You must actively select the multilingual option; this is important.

What happens if the customer's voicemail answers during an outbound call?
In this case, our system automatically detects the voicemail.

Can the AI handle multiple calls in parallel?
Yes, the AI can handle multiple calls simultaneously. The AI agent can cover up to 15 calls at the same time. If more than 15 people call, additional calls are placed in a queue.

Can I forward calls back to the central office if the caller does not want to speak with the AI?
Yes, this is possible.

Can calls be transferred from one assistant to another?
Yes, this is possible! Simply use forwarding to switch to another assistant.

Can I select the assistant for outgoing calls via API?
Yes, you can select the assistant for outgoing calls via the "fromNumber" setting. This can even be done dynamically.

Can Fonio directly make an outbound call?
Yes, this is possible! Fonio can call leads who register via a contact form, qualify them, and schedule an appointment.

Why should I create multiple assistants?
If you have different use cases that do not overlap, it can make sense to create multiple assistants. For example, if your company has two completely different business areas, keeping assistants separate helps maintain clarity.

How is forwarding billed?
We charge only 6 cents per minute for active forwarding.

Can I specify in the prompt after how many rings the call is recalled if the desired person does not answer?
This is currently not possible. A fixed 30 seconds is set.

Does the AI wait during call forwarding until the participant answers?
Yes, the AI currently waits 30 seconds before recalling the caller.

How can I solve the problem with call forwarding so that the caller's number is displayed?
You need to configure this in your telephone system. Check the call forwarding settings to ensure the caller's number is forwarded.

Can I tell the AI to perform call forwarding only during business hours?
Yes, this is possible! You can instruct the AI to forward calls only during business hours.

Can I automatically reject callers if they have problems?
Yes, this is possible! You can use a function that automatically rejects callers and forwards them to an employee if there are difficulties.

Can Fonio be used in a call center to activate after a longer wait time?
Yes, this is possible! Fonio can be set up to start activation only after a certain wait time.

Does the AI recognize when an outbound call reaches an answering machine?
Yes, the AI recognizes this and then hangs up.

Does each assistant cost extra and do I have a separate phone number for each assistant?
You can use the assistants for free! Phone numbers, however, cost €9 per month.

How many calls can the AI agent handle simultaneously? What happens if 10–20 people call at the same time?
The AI agent can handle up to 15 calls simultaneously. If more than 15 people call, additional calls are placed in a queue.

3. Languages, Voices & Dialects

Can the AI speak multiple languages or dialects?
Yes, Fonio supports many languages. In multilingual mode, it can even automatically switch between eight languages during the conversation. For certain dialects or special speech modes, we offer different voices.

What does it cost if the AI uses additional languages or voices?
All available languages are always included; no additional costs arise.

How fast are the reaction times for text-to-speech and speech-to-text?
Our reaction times are usually about one second or slightly less, depending on server load.

Do you have your own STT/TTS?
We use the best available STT and TTS technologies, which we can easily swap at any time.

Is Maria's voice GDPR-compliant? How do I know which voices are compliant?
It depends on the voice provider. Currently, voices from Elevenlabs are not yet GDPR-compliant, while voices from Azure in Europe are fully compliant.

Does the '#' character have a special meaning in the prompt?
Yes, the "#" character is used in Markdown format to create headings.

Is it better to formulate complex processes in natural language or with Mermaid charts?
For complex processes, it can be helpful to use both approaches. Natural language is good for explanations, while Mermaid charts provide a visual representation.

Can Fonio switch languages during a conversation if my counterpart wants to speak English?
Yes, Fonio can switch languages if your conversation partner wants to switch to English.

Can I have all languages listed in the prompt?
Yes, that is possible!

4. Integrations, API & Automation

Can I connect Fonio with other systems like CRM, online shops, or tools? Can the AI access APIs?
Yes! Fonio offers an open API with which you can connect almost any system – e.g., CRM, ERP, calendars, ticket systems, automation tools like Make, n8n, or Zapier.

How do I integrate my website into the AI to use information? Do I have to create PDFs?
You can integrate your website via the "Web Search" tool by simply entering the domain. PDFs are not necessary if you want to make the information from your site available.

Where do I find the SIP connection?
You can find the SIP connection under the “Phone Numbers” tab. Just click there!

How do I create a personalized greeting with webhook data?
You can implement this in the start prompt. You can define individual variables and set fallback options if first or last name are empty.

Does the calendar function also work with other tools like Bookings?
Currently, the calendar function works natively only with cal.com. For other tools like Bookings, integration via API is possible if supported.

Which automation software is recommended?
We recommend n8n as automation software.

Is there a resource to learn how to integrate the interfaces?
Yes, a video showing exactly that will be published soon!

How do I pass the {{fromNumber}} to the API?
You pass the fromNumber in the body of the API request.

Can I include the contact's name in the start message when using the inbound webhook and the result is positive?
Yes, you can! If the inbound webhook successfully provides contact info, you can include the name in the start message.

Can I update the knowledge base automatically?
Yes, this is possible with n8n. You can use the Fonio API to perform updates.

Is there a native integration with HubSpot, and do you use HubSpot yourselves?
Currently, we have no native integration with HubSpot. However, you can integrate HubSpot via automations like n8n.

What is a Pre Call Hook and how do I integrate the caller's order history into the prompt?
A Pre Call Hook helps you collect important information before the call and include it in the conversation. To include the caller's order history, you can mention in the prompt: "Hello, I see you last ordered [product] on [date]."

Does the knowledge base have an API or can I only use PDFs?
Currently, you can only embed PDFs on the Fonio platform. You could create a knowledge base outside Fonio with an API connection.

Can I integrate my own workflows, e.g., for quote generation? Can the agent also read the offer aloud?
Yes, you can integrate your own workflows for quote generation. The agent intelligently selects these and can also read the offer aloud.

Can the AI query the delivery status of an order when connected to CRM or ERP systems?
Yes, this is possible via an API connection during the call.

Can I store a list of names and numbers in the knowledge base if my CRM has no API?
Yes, this is technically possible. This way, the AI can address the caller by name.

Can I refer to a database in the car rental example that the AI assistant can use to check current models?
Yes, this is possible! If the car dealership has the necessary systems, an API connection can be set up.

Does your API support authentication for post-processing?
Yes, our API supports authentication for post-processing.

How can I apply as an automation/AI service provider partner?
You can simply apply via our contact form. Fill in all required information and we will get back to you as soon as possible.

5. Appointment Scheduling & Calendar

Can the AI book appointments or access calendars?
Yes, the AI can independently book appointments via cal.com or via API and work with common calendars like Google, iCloud, or Outlook.

Do I need an email for appointment booking?
No, you can also provide your mobile number. You will then receive confirmation via SMS.

Do I have to create multiple events in tools for multiple calendar entries on cal.com? And how should the descriptions look?
Yes, you should create a separate tool in Tools for each type of calendar event. Make sure the tool names are meaningful.

Can business hours be set for AI usage?
Yes, this can be implemented! You can specify that the AI works outside business hours, e.g., from 6:00 pm to 8:00 am, and during business hours your employees handle inquiries.

6. SMS, Email & Post-Processing

Can the AI send SMS or emails and provide transcripts after the conversation?
Yes! Under “Post-Processing” you can set when and to whom SMS or emails should be sent. After each conversation, you receive a transcript.

Are there additional costs for using SMS?
Yes, additional costs may arise. These are transparently indicated and are about 15 cents per SMS.

Do we receive the recording afterwards?
Yes, the recording is sent to all participants after the event.

Can I make links from post-processing accessible to non-logins?
Currently, this is not possible. However, we plan a user management system in the future that will enable this.

Is the SMS sent via a Fonio number or do I have to configure my own number?
You do not need to configure your own number; this is done automatically via Fonio.

Why is my email address not recognized correctly?
It can help to give more precise instructions in the prompt about how often to ask and what to do if nothing is recognized.

Advanced Email Recognition Protocol

1. ACTIVE PROMPTING FOR SPELLING: When asking for an email, actively guide the customer: “Could you provide your email address and spell it out for confirmation?”

2. PHONETIC ASSISTANCE: When the customer spells the address, remain completely silent (no “Mhm” or “Yes”). If a letter is unclear, ask specifically using the phonetic alphabet (e.g., “Did you mean B as in Bravo or P as in Papa?”)

3. SPECIAL CHARACTER TRANSCRIPTION: “At” or similar terms → @; “Dot” or “Point” → .; “Dash” or “Hyphen” → -; “Underscore” → _

4. CONFIRMATION LOOP (ESSENTIAL): Once the customer finishes, ALWAYS repeat the email address back for confirmation. Spell out critical parts, e.g., “I have noted: ‘m’ as in Max, ‘u’ as in Ulrich, ‘s’ as in Siegfried, ‘t’ as in Theodore, then the at‑sign, and then gmail dot com. Is that correct?”

5. ERROR FALLBACK: If after the second attempt the email is still not correctly captured, say politely: “I want to make sure the confirmation reaches you. I’ll send you an SMS to this number, and you can simply reply with your email address.”

Structured Data Recognition (Customer Numbers, IDs)

For customer numbers or similar structured identifiers, specify the expected format in the prompt. For example: “A customer_number always consists of 11 digits starting with U…”. This helps the AI understand the expected pattern and reduces transcription errors when capturing alphanumeric identifiers.

Implementation Tips

• Test these protocols with your specific use cases.

• Adjust phonetic examples to match your target audience’s language preferences.

• Consider creating fallback SMS workflows for critical data collection.

• Monitor transcription accuracy and refine protocols based on real‑world performance.

7. Internet Research & Knowledge Base

Can the AI research on the internet or access knowledge bases?
Yes, there is an integrated search function with which the AI can fetch live results from the internet. For large amounts of information, it is better to use the knowledge base where you can upload PDFs.

How much information can I put into the prompt or knowledge base?
The prompt can be up to 100,000 characters long (approx. 20 A4 pages). Larger amounts of information or documents like terms and conditions, product datasheets, etc., are best uploaded as PDFs to the knowledge base.

Is a PDF as a knowledge base faster than a website?
Yes, generally a PDF document is faster to load and provide than a website, especially if the website contains many graphics or interactive elements.

Do you also support other formats like markup or DOCX in the knowledge base?
Currently, we only support PDF files, but we are working on expanding the options.

Is fonio.ai already active for Switzerland?
Yes, Fonio is now also active in Switzerland – even with Swiss voices!

Which LLM does Fonio use?
We currently use models from OpenAI. These are GDPR-compliant and can be easily replaced if needed.

Does the AI also search subpages or only the specified website?
The AI searches the entire specified domain, including all subpages.

Can I upload company information as a PDF to the knowledge base?
Yes, this is possible! You can upload the information as a PDF to the knowledge base.

Is there a limit for the knowledge base?
Currently, there is no limit for the knowledge base. We have already successfully tested with over 300 pages of documents.

Is there a recording of the advanced part of the webinar?
Yes, the recording is sent by email to all participants.

8. Data Protection, GDPR & Compliance

How is data protection, GDPR, and EU AI Act handled at Fonio?
We store all sensitive data on secure servers in Germany (Hetzner, Nuremberg), fully EU-compliant. Additional services like certain voice providers or tools can transfer data to the USA on request – you can control this yourself.

Does the AI have to say on the phone that it is an AI and that the call is recorded?
Yes! This is mandatory under GDPR and the EU AI Act. The AI always introduces itself as AI and points out the recording or transcription. The caller can then decide if they agree – if not, the transcript is automatically deleted.

Is “I am the virtual assistant of company XY” enough as a notice?
The topic is still legally new. It is important that it is clear that it is an AI. Most customers expect transparency and understanding in case of errors.

Should I obtain the caller's consent to data protection at the beginning of the call?
Yes, this is recommended. It ensures transparency and trust.

How long does the transcript remain in the system?
The transcript remains in the system for up to 30 days.

Where are the documents processed and stored?
Yes, the documents are also processed and stored in Europe.

Is there a standard template for the AVV (data processing agreement)?
Yes, our AVV is part of the terms and conditions and can be viewed from page 7.

9. Names, Data & Variables

Does the AI always recognize all names, addresses, or data correctly? What to do in case of errors?
The AI tries its best, but with unusual names, addresses, or spellings, errors can occur. If in doubt, have names spelled out and activate detailed information capture under “Technical” with examples. You can avoid errors with numbers by also writing them out in the prompt (e.g., “150 (one hundred fifty)”).

What happens if a variable like the first name is missing in the prompt from the inbound webhook?
You can always specify a default text (fallback) in the inbound webhook tool, e.g., “Hello, nice to meet you.” This way, the greeting always sounds friendly – even if some information is missing.

How can I improve name recognition?
To optimize name recognition, you can insert a list of names in the prompt.

Can I enter an address with house number, staircase, floor, and door?
Yes, that works! The AI can process such addresses like Musterstraße 12/3/DG/5 without problems.

10. Prompt Design, Behavior & Answers

How do I design the prompt so that the AI, for example, makes pauses, pronounces words correctly, or follows certain sequences?
Write in the prompt how the AI should proceed (e.g., “Ask for one piece of information at a time”). For pronunciation of words or names, you can use phonetic spelling or descriptions.

Can I put unlimited rules, FAQs, and knowledge into the prompt?
Yes, up to 100,000 characters are allowed. For even more info, use the knowledge base (PDFs, terms and conditions, manuals, etc.).

How are tools called in the prompt?
If you want to use a specific tool, simply specify which tool you want to use, for example, “use the tool ‘Tool 1’”.

How does the generator work and how do I use it?
The generator in ChatGPT helps you create content. You specify what you need and can directly insert the text into the desired format.

Does the length of the prompt or the number/length of uploaded PDFs affect the AI agent's response time?
Yes, but only minimally. The delayed response time is usually negligible.

Do you have a sample prompt template for optimal formulations with hashtags?
Yes, we offer templates for four general use cases.

Can I build branches, e.g., different questions for existing and new customers?
Yes, this is possible! You can design different questions for existing and new customers through logical branching in the prompt.

How complex can a prompt be? When does it become too long?
A prompt can be up to 100,000 characters long. Sometimes it is better to split it into several sections.

How long can prompts be?
Prompts can be up to 100,000 characters long.

Is there a specific order for prompting?
We recommend following the order of our sample prompts, but this is not mandatory.

How large is the prompt context window?
The prompt context window covers 100,000 characters, which is about 20 A4 pages of text.

Do you have templates for configurations or prompts to get started?
Yes, in the prompt window you will find four templates. You can use these to develop your use case.

Is there a structure or grouping for prompts?
In the prompt, we recommend following the structure of the sample prompt. The structure is created by categories marked with # as headings.

How many PDF documents can I upload in the prompt and can I manage them?
There is currently no limit for uploading PDF documents in the prompt. However, you can manage all uploaded documents.

How can I structure my prompt? What is the '#' in the presentation about?
You can best structure your prompt in Markdown format. The '#' is used to mark headings.

How do you support writing prompts and does it cost extra?
We provide templates that help you write prompts. Additionally, we offer complete assistant setup for a fee.

How can I reduce interruptions by our AI during calls?
You can adjust this in the technical settings. Look there for options for conversation control.

How do I prevent the AI from getting stuck in loops and repeating the same question?

Provide clear instructions in the prompt regarding how many times the AI is allowed to ask for specific information. For example:

"Ask for the name only once. If the customer does not provide the name or if you do not understand it, proceed with the conversation."

By doing this, you prevent the AI from getting stuck in a loop and frustrating your customers.

11. Prices, Costs & Refunds

What does Fonio cost? Are there fixed costs or a setup fee?
You only pay for what you actually use. There is a minimum starting credit of €300. You pay between 25 and 35 cents per call minute, depending on volume. Each own phone number costs €9 per month, which you can remove anytime. There are no other setup fees.

Does testing the AI cost money?
Yes, currently testing costs a few cents per minute because costs also arise for us. We currently give a 50% discount on the minute price. Frequent testers often receive goodwill minutes or credit from us.

Can existing customers also use the voucher?
Yes, existing customers can also use the voucher for their next top-up.

How do I enter my credit code as an existing customer?
If you already have an account, you can redeem the credit code with your next top-up.

Do I have to book the new credit by tomorrow noon to use the voucher code, even if I already have credit?
Yes, the voucher code is only valid until tomorrow noon.

Can I start with less than €300 starting credit?
Currently, €300 is the minimum credit to start with Fonio. However, we offer a 30-day money-back guarantee.

Why are costs only incurred for testing?
Costs for testing arise due to the infrastructure we provide, as well as the tools and use of the LLM. But don't worry, we offer a 50% discount on testing.

Do costs refer to net AI time or gross time?
Costs refer to the entire call duration, from the moment the AI picks up until hang-up.

Does each assistant cost extra and do I have a separate phone number for each assistant?
You can use the assistants for free! Phone numbers, however, cost €9 per month.

Does the €9 tariff also apply to CH numbers?
Yes, the €9 per month tariff also applies to Swiss numbers.

How do you support writing prompts and does it cost extra?
We provide templates that help you write prompts. Additionally, we offer complete assistant setup for a fee.

12. Invoices & Taxes

Can I use Fonio as a private person? How is it with invoices and tax numbers?
Yes, that works! If you do not have an AT or DE tax number, you can simply leave this field blank during registration. Private persons get VAT shown on the invoice.

Can I register with Fonio with my company if my location is outside Germany or Austria?
Yes, that works! If you operate internationally, you can simply register on the platform. If you need an invoice showing your VAT ID, just let us know at support@fonio.ai.

13. Partners & Integration

I want to recommend Fonio as a partner or use it for my own customers – is that possible? Is there a partner program?
Yes! We are always happy about new partnerships – whether AI consultants, software developers, or companies. Info is available on the website under “Become a Partner” or just write to us directly.

14. Technology, Special Features & Improvements

How can I adjust the AI's speaking speed, sensitivity, or creativity?
In the “Technical” section, you can individually adjust speaking speed and sensitivity. For some use cases, it makes sense to increase or decrease creativity. You cannot influence latency here.

Latency is too high, what can I do to improve it?
Under “Technical” you can select the speech processing model. Here you will also find a note about which are particularly fast and offer low latency.

What makes Fonio special compared to other providers?
We build our software ourselves and rely on flexible, EU-based technology. Since we optimized our telephone AI for German from the start, email addresses, license plates, and special data are reliably recognized, our latencies are low, and data protection is at EU level.

What to do if the AI calculates incorrectly?
The AI is not a calculator. For complex calculations, an external API is recommended, whose result is then integrated into the conversation.

Do I no longer have to buy a phone number if I want to use SIP?
Yes, exactly! With SIP you can assign an extension, e.g., 74 in your self-hosted 3CX. When the employee dials 74, the AI from Fonio takes over.

Can I also use SIP for outbound calls once it is ready?
Yes, that will be possible!

Is a user management planned so that multiple employees can work on settings together?
Yes, user management is in progress and will be available soon.

How does sentiment analysis work during calls? Can I be notified if the AI detects that a customer is very upset?
Sentiment analysis of calls is partially possible, especially through variable extraction.

How many calls can an agent conduct simultaneously in outbound?
An agent can conduct up to 15 calls simultaneously in outbound.

How many calls can an agent hold simultaneously? Can multiple outbound calls be made simultaneously to increase productivity?
An agent can hold up to 15 calls simultaneously. Theoretically, you could also make multiple outbound calls at the same time.

When will SIP trunk capability be available so I can use an extension of my telephone system?
SIP trunk capability will be available very soon.

How can I replace my T-Mobile voicemail with Fonio?
To replace your T-Mobile voicemail with Fonio, you need to set up call forwarding from your phone or mobile to Fonio.

Can the AI's response time fluctuate depending on server load?
Yes, response times can vary, especially when servers are heavily loaded.

Can I start recording during a call if there are misunderstandings?
This is currently not possible. The call is always transcribed and recorded if you have selected this.

How large can the context window be?
The context window can be up to 100,000 characters.

How many calls can the AI answer simultaneously?
The AI can officially handle up to 15 calls simultaneously, but actually more are possible.