1. Who is responsible
The controller responsible for your data is: Yahia Alzaim - Tellu
Lindenallee 8
18273 Güstrow
Germany
Contact for all privacy questions: support@mytellu.app
2. Your account
To create an account you sign up with your phone number or your email address. We store your phone number or email, your username, your display name, an optional profile photo, your app language and your time-zone offset (which is shown to your friends so they know your local time). If you add a short bio (up to 140 characters) to your profile, any Tellu user who opens your profile can see it; an optional cover photo is shown to your friends only.
Calls with friends can show a map with both countries. On this call map your friend sees your country only if you turn on "Show my country to my friends" (off by default): the app then sends the country of your phone network — the call map never uses your exact location or GPS. Without it, we only show the country of your phone number when your phone’s time zone matches that country. You can hide the map in Settings at any time. Sending your location in a chat is a separate feature that you only use on purpose (see section 4).
Phone numbers are verified by an SMS code sent by our SMS verification provider. Email addresses are verified by a code sent by our email delivery provider.
Legal basis: performance of our contract with you (Art. 6(1)(b) GDPR).
3. Your contacts
If you allow access to your contacts, the app sends our server a one-way fingerprint (hash) of each phone number in your address book, not the numbers themselves, to find out which of your contacts use Tellu. Contact names are not sent. The fingerprints are used only for this comparison and are not stored on our server. You can use Tellu without granting this permission.
Legal basis: performance of the contract and our legitimate interest in helping you find your contacts (Art. 6(1)(b) and (f) GDPR).
4. Messages and media between Tellu users
Messages, photos, voice messages and other files you send are stored on our servers so that they can be delivered to the recipient and synced to your devices. Videos are deleted from our servers 30 days after they are sent; copies already downloaded stay on the devices. They are encrypted in transit (TLS) and stored encrypted on our servers (AES-256), but they are not end-to-end encrypted: our server can decrypt them, for example to deliver them, show notification previews and provide translation.
Encrypted chats are the exception: when you start an encrypted chat with someone (marked with a lock), its messages, photos and voice messages are end-to-end encrypted on your phone using the Signal protocol design (X3DH and Double Ratchet). Our server only stores and forwards the encrypted data and cannot read it; the keys stay on your and your contact’s phones only. Because of this, encrypted chats cannot be restored on a new phone, and smart translation and AI features are not available in them (on-device translation still works). We still see that a message was sent, between whom and when.
Messages are kept until you delete them ("delete for everyone"), until they expire if you turn on disappearing messages (24 hours or 7 days), or until your account is deleted.
Location in chats: only when you choose to send your location in a chat, the app reads your phone’s location once — there is no live or background tracking — and sends it as a message with the coordinates, their accuracy, the city and country (looked up on your phone) and your time-zone offset. The recipient can open it in a map app. A location message is stored, encrypted and deleted like any other message (end-to-end encrypted in encrypted chats). Map links you paste are sent as normal text messages. Postcard stamp in the Tellu camera: only when you use the postcard mode or the stamp, the app asks for your location and reads it once to look up your city on your phone; it is not sent to us, and the city name appears only on the photo you choose to send. If you decline, the stamp shows your country only. Legal basis: performance of the contract (Art. 6(1)(b) GDPR).
If you report someone, we store the reason, any details you write and the reported person’s latest messages in that chat (for encrypted chats only the message you report, which your phone sends with the report), so that the Tellu team can review it. The reported person is not told who reported them. Reports are deleted when either account is deleted.
We also process your online status ("last seen", which you can turn off), your friends list, blocked users and reactions. We also keep an encrypted backup of your circles (for example family, work or clients: the groups you sort people into) and their rules, so they can be restored on a new phone, as well as the people you do not accept calls from; both are deleted with your account. If you add your birthday to your profile, we store it encrypted and show it only to the people you choose (nobody, all your friends, or the people in your family, close and friends circles); you can change or remove it at any time. The same encrypted backup includes the settings you keep for your people (for example relationship, notes, ringtone and mute), so they move with you to a new phone. Tellu works on one phone at a time: to protect your account we store the name of the phone it is active on (for example "Samsung Galaxy A54") and your last 10 sign-ins (phone name and time), and we email you when your account is signed in on a new phone.
5. Voice and video calls between Tellu users
You can make free one-to-one voice and video calls with other Tellu users. Calls are encrypted in transit and are not recorded.
Direct calls: calls with your friends and mutual contacts are normally connected directly between the two phones (peer-to-peer), as in other messaging apps, so the audio and video do not pass through our servers. To connect directly, the two phones exchange their network addresses, so each side’s IP address can be visible to the other person’s phone. An IP address can reveal your approximate location (for example your city) and your internet provider. To find its public address, your phone contacts a STUN server on our server and, as a fallback, a public STUN server run by an external provider, which sees your IP address. Calls with other people go through our server.
"Protect my address in calls": if you turn on this setting (off by default), your calls are never connected directly: calls you make go through our server, and calls you receive are routed through our relay server (TURN, on our own server in Germany), so the other person does not see your IP address. Calls are also routed through this relay when a network blocks direct connections. The relay only forwards the encrypted data and does not store it; the app receives temporary relay credentials that expire after 24 hours.
Call quality ratings: after some calls the app may ask how the call quality was (three levels). We store your rating with your account, together with the call length and whether it was a video call, a direct call and had connection problems — not the content of the call and not who you called — to improve call quality. Ratings are deleted with your account.
Video effects: colour filters, Touch-up, Enhance, face lenses, Follow me and gesture reactions (including the hand kiss and the lip kiss) are processed only on your phone; no camera image is sent to us or to anyone else for them — the other person simply receives your call video as usual. Face lenses and gesture reactions use open-source on-device models: a face landmark model (about 3.8 MB), which the app downloads once from mytellu.app the first time you choose a lens or turn on gesture reactions, and a gesture recognition model (about 8 MB), which it downloads once from mytellu.app when you turn on gesture reactions (off by default). Both are kept on your phone. The points of your face that a lens or a kiss gesture needs are calculated on your phone and are never stored or sent. Like any visit to our website, these downloads use your IP address, but no account data is sent. Filters and lenses are not remembered: each new call starts without a filter or lens.
Legal basis: performance of the contract (Art. 6(1)(b) GDPR) and our legitimate interest in good call quality and in preventing abuse (Art. 6(1)(f) GDPR).
6. Calls to phone numbers
When you call a regular phone number, we pass the dialled number and your caller ID to our telephone carriers so they can connect the call. We store a call record (dialled number, country, time, duration, price and technical route) for billing, for handling complaints and to prevent fraud. Calls are not recorded.
Legal basis: performance of the contract (Art. 6(1)(b) GDPR) and legal obligations (Art. 6(1)(c) GDPR).
7. Payments, balance, offers and eSIM
Card payments are processed by Stripe. We never receive your card number; we only store the amount, the date and the status of each top-up. Your balance and all transactions (top-ups, calls, offers, eSIM purchases) are recorded in your wallet.
Travel eSIM plans are supplied by our partners, wholesale providers of mobile data plans. We do not send them your name, phone number or email; we store the order details (plan, ICCID, activation code and data usage) so you can install and manage your eSIM.
Mobile top-up: when you send credit to a phone number, we pass that phone number, its country and network, and the amount to our mobile top-up providers so they can deliver it; we do not send them your name or email. We store the order (number, network, amount, price, status and any voucher code) so you can see it in your history, for refunds and to prevent fraud.
8. Smart features (translation, writing assistant, smart mediator, support assistant)
If you use smart translation, the writing assistant or the smart mediator, the text concerned is sent to our AI provider to create the result. When you contact support, the support assistant receives your support conversation and the information it needs to help you (for example your balance and your recent calls). We do not store this text for these features, except the support conversation itself.
The writing assistant and the smart mediator (a summary of the chat, what the other person is asking for, and suggested replies) work only when you open them, and the first time the app asks for your consent. When you use the smart mediator, the latest text messages of that conversation (up to 40), from both you and the other person, are sent to our AI provider. Nothing is sent to the chat automatically: you decide what, if anything, to send. These features are not available in encrypted chats.
Some features run on your phone only: offline translation, recognising text in photos and blurring faces. Speech recognition (dictation, voice messages, live call captions) uses your phone's speech service; if on-device recognition is not available, the audio may be processed by the provider of your phone’s speech service.
Legal basis: your consent and the performance of the contract (Art. 6(1)(a) and (b) GDPR); for the messages of the other person, the legitimate interest of both of you in understanding each other (Art. 6(1)(f) GDPR). You can withdraw your consent at any time by no longer using these features.
9. Live captions and translation in calls
If you turn on captions or translation in a call, speech is converted to text on the phones by the phone's speech recognition (see section 8). Only text is processed, never a recording of the call.
In a call with another Tellu user, the text of what you say is sent through our server to the other person’s app, so that it can be shown and translated there, and the text of what they say reaches your app in the same way. It is passed on and not stored.
Automatic start for the other person: in a call between two Tellu users, when one person turns on translation, the other person’s phone also turns on speech-to-text automatically, so that translation works in both directions. This happens only once per call, and not if that person has turned it off themselves. Their phone shows a notice saying that the other person turned on translation and that what they say is now translated for them; they can stop it at any time by tapping Translate. Here too, speech recognition runs on each phone, and only the recognised text is sent to the other person through the chat connection; it is not stored on our server.
In a call with a regular phone number, the other person does not use Tellu: their voice in the call is converted to text on your phone so that you can read and translate it. This means that the speech of a person who is not a Tellu user is processed. If you use captions in such a call, please let the other person know.
Translation: unfinished parts of sentences are translated on your phone. Complete sentences of the other person — and parts of sentences after a short pause — are translated by our smart translation when it is available to you: it sends the sentence together with the last few sentences of the call (from both participants, for context), both display names and the speaker’s Arabic dialect if known, to our AI provider; otherwise they are translated on your phone. The text is used only to return the translation and is not stored by us. The captions are shown only during the call.
Legal basis: performance of the contract with you (Art. 6(1)(b) GDPR); for the other participant, the legitimate interest of both participants in understanding each other across languages (Art. 6(1)(f) GDPR). The processing is limited to text, happens only while the feature is on, and nothing is stored.
10. Bridge links (guests without the app)
If someone talks to you through a Bridge link, we process the name the guest enters, the messages exchanged and, if the guest agrees, a browser notification subscription. The guest's IP address is used briefly to prevent abuse and is not stored permanently. The guest's browser keeps a guest key in its local storage so that the guest can return to the conversation. Guest data and messages are deleted 30 days after the link is closed or expires.
11. Notifications, support and statistics
- Push notifications are delivered by the push service of your phone’s operating system and may contain the sender's name and a short preview of the message.
- Support requests are stored with your messages and basic device information (app version, operating system, language) until your account is deleted. Emails to support@mytellu.app are received and stored in our mailbox at our email hosting provider (EU data centre).
- If you rate Tellu in the app, we store your stars and comment with your account. Only if you give 4 or 5 stars and tick the consent box may we publish your comment on mytellu.app, with your first name and country only. You can ask us to remove it at any time; it is deleted with your account.
- To improve the app we record on which days the app was used and when you first used certain features (for example your first call). We do not use third-party analytics or advertising trackers.
12. Website
Our website sets only one cookie, and only if you choose a currency with the currency switch ($ / €): the cookie "cur" remembers this choice for one year so that prices are shown in that currency. It contains nothing else and is not used for tracking. We count page views in aggregate without storing IP addresses. Fonts and flag images are served from our own server, so the website does not send your IP address to third parties. If you join the iPhone waiting list, we store your email address only to notify you about the iPhone app.
13. Service providers
We use the following providers, who process data on our behalf or as independent services: Hetzner (server hosting in Germany, including our call relay) and Stripe (payments). We also use providers in these categories: SMS verification, push notifications and app distribution (the operating-system and app-store provider), AI services (smart translation and assistants), email delivery (verification codes) and email hosting (our support mailbox, EU data centre), a public STUN server, wholesale eSIM providers, mobile top-up providers and telephone carriers. On request we will tell you which providers receive your data (Art. 15 GDPR). Some of them are located outside the EU, in particular in the USA; transfers are based on the EU-U.S. Data Privacy Framework or EU Standard Contractual Clauses.
14. How long we keep data
We keep your data as long as your account exists. When you delete your account, your profile, messages, media, contacts, friends, support requests, call ratings and usage statistics are deleted. Payment records (top-ups and charges) that we must keep for accounting and tax purposes are kept for the statutory periods (up to 10 years), but separated from you: your username is replaced by a random code and notes such as phone numbers are removed. Call records keep who called whom for 6 months (for billing and complaints); after that only the date, duration, country and cost remain. Server logs are rotated automatically and old entries are deleted. Backups are overwritten after 14 days at the latest.
15. Your rights
You have the right to access, rectify and erase your data, to restrict processing, to data portability and to object to processing based on legitimate interests. Where processing is based on consent, you can withdraw it at any time. To exercise your rights, write to support@mytellu.app. You also have the right to lodge a complaint with a data protection supervisory authority, for example the State Commissioner for Data Protection of Mecklenburg-Western Pomerania (Der Landesbeauftragte für Datenschutz und Informationsfreiheit Mecklenburg-Vorpommern).
16. Age
Tellu is intended for people aged 16 and over.
17. Changes
We update this policy when our services change. The date of the latest update is shown at the top.