Privacy policy

This policy explains how your personal data is processed when you use the certifbus.com website (the “site”) or the Android app “Exam Prep for KNX Basic” (the “app”). Unless stated otherwise, it applies to both. It supplements the legal notice of the site.

The controller is Pop Solutions Groupe SAS, Juvisy-sur-Orge, France, registered with the Trade and Companies Register RCS Évry 939 746 749 (SIRET 939 746 749 00018). For any question about your data or to exercise your rights, write to hello@certifbus.com.

For each category, this is the data concerned, its purpose and the GDPR legal basis (Article 6) on which the processing relies. Providing your email address is necessary to create an account; the other information is optional or results from your use of the service. Some of it also reaches us from a training centre that invites you.

• Account. Email address, display name (optional), preferred language and exam date (optional). You sign in with a code or a link received by email, without a password. Purpose: create and secure your account, adapt the language and, if you enter an exam date, send you reminders before the exam. Basis: performance of the service you request (contract).
• Practice. Your sessions (mode, date, duration, score), your answers, your progress per question, the questions you flag, your history and, on your device, a backup that lets you resume an interrupted session. Purpose: mark your answers, calculate your results and progress, suggest targeted revision, a daily routine and a streak. Basis: performance of the service (contract). Without an account, free sessions are not saved on our servers: they stay in your browser or on your device.
• Payment. When a paid access is purchased, the payment is processed by Stripe: CertifBus neither receives nor keeps your card number. We keep the offer, the amount, the currency, the date, the access duration, the Stripe identifiers of the session and of the payment, and the address to which the receipt was sent. Stripe collects the billing information it needs (for example an optional VAT number) and keeps it under its own policy. For a purchase made in the app, processed by Google Play, we keep the order number, the nominal amount of the offer, the date and the access duration; Google processes the payment and sends us no bank details. Purpose: grant and prove your access, issue invoices and receipts, keep our accounts. Basis: contract and legal obligation.
• Training centres. If a centre invites you, it gives us your email address so that we can send you the invitation. Once you accept, we keep your link to the centre and the access it provides. Your results are shared with the centre only if you turn on sharing: it is optional, can be withdrawn at any time and has no effect on your access. The centre then sees the results of the sessions you start for it after you turned sharing on, over the last 30 days (scores, durations, skills to reinforce), never your personal history. The printable attestation, however, lists the shared sessions (date, mode, number of questions, duration) for the whole duration of your active access, not only the last 30 days. Sessions done in the app are personal and are not shared with a centre. Managers of a centre space are identified by their email address and role. Basis: performance of the service for the access, consent for sharing. The centre then uses this information for its own teaching follow-up; contact it about that use.
• Messages and reports. Your email address, your message, your language and, if you are signed in, your account identifier (determined by our servers from your session) when you use the contact form, request a pilot for a centre or report a question. A reported question is suspended while our team reviews it, and the team reads the details you gave. Purpose: reply, handle the request and correct content. Basis: legitimate interest in handling the requests we receive and, for centres, pre-contractual steps.
• Emails. We send essential emails (sign-in code or link, purchase receipts, centre invitations), service reminders (exam date, access ending soon), learning support (mock exam debriefs, preparation rhythm, weekly review) and, only if you asked for them, commercial communications (tips after the free trial, newsletter). We keep the list of messages sent, your preferences and unsubscriptions, and technical delivery feedback (bounce, complaint); we do not track opens or clicks. Basis: contract for essential messages and service reminders, legitimate interest for learning support (which you can decline), consent for commercial communications. Optional messages include an unsubscribe link, and the email preference centre on the site lets you choose by category.
• Optional sign-ups. Email address (and exam date if you enter one) given for the newsletter, the waiting list or tips after a free trial, and any answer to a short email survey. Purpose: send you what you asked for and understand what holds back your preparation. Basis: consent.
• Browser notifications (site only). If you turn them on: the technical address of the subscription and its encryption keys, your language, your time zone and the device type. Purpose: send you the daily reminder. Basis: consent, which you withdraw by turning notifications off. The app does not use this mechanism (section 4).
• Technical logs. Our hosting and security providers process the IP address, the date and the request headers to deliver pages, protect the service against abuse and diagnose errors. Basis: legitimate interest (security and proper functioning of the service).

No decision based solely on automated processing and producing legal effects concerning you is made. Scores, progress indicators and revision priorities are practice aids, not an official assessment or a certification.

This section only concerns the site. The app uses none of the technologies described here (section 4).

Without your consent, the site only uses:

• Strictly necessary storage: your sign-in session, your language, your cookie choice and the backup of your current session (cookies and local storage in the browser). It is not used for audience measurement or advertising.
• Vercel Web Analytics, which counts the pages viewed. It is loaded without waiting for your choice in the banner, except on the pages of your account, centre spaces and administration. Basis: legitimate interest (traffic statistics).
• Loading of Google Tag Manager on public pages, in denied-consent mode (Google Consent Mode v2): until you accept, the advertising and analytics storage permissions sent to Google are denied. As with any content served by a third party, Google receives your IP address when it loads.
• Security filtering of requests (Senthor): to detect automated access, in particular by artificial intelligence robots, the IP address, the path of the requested page (without parameters) and the request headers (excluding cookies and authorisation) are sent to Senthor when a public page is requested. The system is currently used in observation mode. Basis: legitimate interest (site security).

Only with your consent (“Accept” button of the banner):

• CertifBus journey measurement: a random identifier specific to the tab, the entry page, the referring site’s domain, campaign parameters from a closed list and the main steps of the journey (home and pricing pages viewed, start and end of a free practice session, start of a payment). It contains neither your email nor your answers. The identifier expires after four hours of inactivity or twenty-four hours in total. After a confirmed payment, the purchase is linked to this journey only if you had accepted the measurement. Basis: consent.
• Google Analytics and Google Ads, through Google Tag Manager: if you accept, the storage permissions are granted and the tags in the container may measure audience and advertising conversions. After a confirmed purchase, the purchase event (amount, order number, offer) may be sent to them with a hash (SHA-256) of your email address, to measure advertising conversions. Basis: consent.
• PostHog: audience and usage measurement (page views, page exits, interactions), hosted by default in the European Union. PostHog is configured to create a profile only for identified people, and the site does not identify you. Basis: consent.
• Microsoft Clarity: analysis of browsing behaviour to spot usability difficulties. Basis: consent.

These tools are not loaded on the pages of your account, centre spaces, administration, sign-in, or during a practice session started for a centre. You can refuse or withdraw your consent at any time with “Manage cookies”: withdrawing stops the measurement in the browser, without erasing what has already been recorded.

The app is used to practise and follow your progress with the same account as the site. Without full access, it shows ads (Google AdMob); it offers an optional in-app purchase, processed by Google Play, and contains no audience-measurement tool of CertifBus’s own.

• Network exchanges. The app communicates with CertifBus servers: the database and authentication (Supabase), and certifbus.com for account deletion and for activating a Google Play purchase. It also communicates with Google (ads, consent, purchase). It is used to sign you in (code or link received by email, or a password for accounts that have one), read the questions your access entitles you to, save your sessions and progress if you are signed in, delete your account and activate your access after a purchase. The links it opens (source of a question, privacy policy, account deletion page) are shown in the device’s browser, and the contact address in the email app.
• Data on the device. The sign-in session (tokens and account details, including the email address), the internal identifier of the signed-in account, the language chosen in the app, the backup of the current training session, the latest result, the day of the last session, the number of extra sets of the day and your reminder settings are stored in the app’s own space, together with, during a sign-in request, a random code that ties the link received by email to this device (valid for two hours at most) and a hash of the last link used, so that it cannot be used twice. This data is excluded from Android’s cloud backup; on some devices, a direct transfer to a new phone may however copy it. Signing out erases the sign-in session, the saved training session, the latest result, the day of the last session and the count of extra sets of the day; the language and reminder settings remain on the device. Uninstalling the app erases everything.
• Ads. Without full access, the free set of the day has no ads; extra sets of questions are unlocked by watching a short ad, and another ad may be shown at the end of those sets; never during a question or an exam, and never with full access. They are provided by the Google Mobile Ads SDK (Google AdMob): Google may receive the device’s IP address (from which it may estimate an approximate location), the Android advertising ID and the app set ID, interaction data (app launches, taps, ad views) and diagnostic data (performance of the app and the SDK), to show and measure ads, produce statistics, prevent fraud and, with your consent where required, personalise ads. In the European Economic Area, the United Kingdom and Switzerland, a Google consent form is shown before the first ad; without full access, you can reopen it from Account tab › gear icon (Settings) › “Ad privacy”. Basis: your consent, collected through this form, for the use of the advertising ID and of information stored on the device and for ad personalisation; without that consent, our legitimate interest in funding the free version with non-personalised or limited ads. You can reset or delete the advertising ID in the Android settings.
• In-app purchase. The 90-day full access can be bought in the app through Google Play: Google processes the payment and CertifBus receives no bank details. The app sends the purchase token to our servers; we use it to obtain the order number and purchase status from Google, verify the purchase, grant the access to your account and withdraw it in case of refund or cancellation. The token is not kept (for a purchase without an order number, only a hash of it is kept). Your account is passed to Google as an irreversible fingerprint.
• Reminders. If you turn them on, the app asks for permission to show notifications, then schedules daily reminders on the device at the time you choose. They are scheduled locally, without a third-party notification service (no Firebase); the chosen time is not sent to our servers. You turn them off in the app or in the Android settings.
• Account. The account is the same as on the site: the active access linked to your account, whatever its origin, is recognised when you sign in. An exam date entered in the app triggers the same email reminders as on the site. You can delete your account from the app (section 8).

The app is installed and updated through Google Play, whose own privacy rules apply to that part.

We do not sell your data. It is accessible to the CertifBus team for support and administration of the service, to providers that process it on our behalf and, for some services, to third parties that process it for their own purposes, with your consent where required:

• Supabase: database and authentication (accounts, sessions, progress, messages). Servers located in Frankfurt (Germany).
• Vercel Inc. (United States): hosting of the site, Vercel Web Analytics statistics and technical logs.
• Stripe: online payment, invoicing and receipts.
• Resend: sending and receiving the service’s emails (sending domain configured in the European region eu-west-1).
• Senthor: detection of automated access to the site (section 3).
• Google (Tag Manager, Analytics, Ads), PostHog and Microsoft (Clarity): audience-measurement and advertising tools of the site, described in section 3. Except for the loading of Google Tag Manager, they only operate with your consent. PostHog is hosted by default in the European Union.
• Google (AdMob, consent form, Google Play): ads and consent in the app, payment and verification of in-app purchases (section 4). For ads, Google acts as a separate controller under its own privacy rules; the ad technology providers listed in its consent form may also receive data to serve and measure ads.
• Your training centre, if a centre has invited you: the access provided and, if you turn it on, the shared results (section 2).

We may also disclose data to an authority where the law requires it.

Some providers are established in the United States or may process data outside the European Union. In that case, the transfer is covered by the safeguards of Chapter V of the GDPR (adequacy decision or the European Commission’s standard contractual clauses). Write to us for information about these safeguards.

• Account and practice data: for as long as your account exists, then erased when you delete it (section 8), including the history of emails sent, except emails tied to a purchase (receipts, sign-in email).
• Payments and purchases (offer, amount, date, Stripe identifiers or Google Play order number, recipient address of the receipts and of the sign-in email sent after the purchase): at least 10 years, the period of the French accounting obligation (Article L123-22 of the Commercial Code); their deletion at the end of that period is not yet automated. This data is kept even after the account is deleted, for that purpose only.
• Support messages and reports: kept as a record of the correspondence, with no maximum period set to date. If you delete your account, they are detached from it but keep the email address and text you sent us. You can ask for them to be erased by writing to us.
• Unsubscribe list: your email address and the date of unsubscription are kept, even after the account is deleted, so that we no longer write to you.
• Deleted account (closed account with the hash of the email address, record of the deletion and, where applicable, the closed record of a centre link, without any email address in clear): kept to show that the request was handled and to link the purchase records, with no maximum period set to date (section 8).
• Audience measurement: the CertifBus session identifier expires in your browser after four hours of inactivity or twenty-four hours, and the recorded events contain neither your email nor your answers. Retention periods of third-party tools (Google, PostHog, Microsoft, Vercel) depend on their configuration and their own policies.
• Your cookie choice: remembered in your browser until you clear or change it.
• Technical logs: kept by our hosting and security providers for their own retention period.

You have the rights of access, rectification, erasure, restriction of processing and objection (in particular where the processing relies on our legitimate interest), the right to data portability where the processing relies on your consent or a contract, and the right to withdraw your consent at any time, without affecting what was done before.

Erasing data without deleting your account. You can ask us to erase all or part of your data without deleting your account: for example your sessions and progress, your flagged questions, your exam date or your messages. Write to hello@certifbus.com from your account’s address and say which data is concerned; we carry out the erasure and confirm it to you within one month. Data that the law requires us to keep, such as purchase records, cannot be erased while that obligation lasts (section 6).

To exercise your rights, write to hello@certifbus.com: we reply within one month. If there is reasonable doubt, we may ask you to prove your identity. You can also delete your account yourself (section 8), unsubscribe from an email or from the preference centre, and withdraw your cookie consent from the site.

If you believe your rights are not being respected, you can lodge a complaint with the French data protection authority, the Commission nationale de l’informatique et des libertés (CNIL, https://www.cnil.fr), or with the supervisory authority of your country of residence.

You can set instructions for the retention, erasure and disclosure of your data after your death, and name a person to carry them out (Article 85 of the French Data Protection Act): write to hello@certifbus.com. Without instructions, your heirs can ask us to close your account.

You can delete your account at any time, from the app or from the account deletion page below. Deletion erases your practice sessions, answers, progress, flagged questions, browser notification subscriptions, optional sign-ups, survey answers, email history (except emails tied to a purchase) and your profile. Your email address is replaced by a hash in the authentication system and you are signed out on all devices; your membership of a centre ends. The technical logs of our hosting providers may contain your email address (for example when you sign in) for their own retention period (section 6).

What is kept: payment data and the recipient addresses of purchase receipts and of the sign-in email sent after the purchase (at least 10 years), the unsubscribe list and the support messages detached from your account (section 6). Managers of an active centre space cannot delete their account on their own: write to hello@certifbus.com.

We also keep, without your email address in clear: the closed account in the authentication system (internal identifier, email address replaced by a hash, creation and last sign-in dates), to which any purchase records remain linked; a technical record of the deletion (internal account identifier, date and origin of the request), so that we can show that your request was handled; if you were enrolled in a centre, the closed record of that link, without your results, which accounts for the access the centre used. No maximum period has been set to date for these items.

The service is intended for adults, professionals or people in vocational training. It is not intended for minors and we do not knowingly collect data about them. If you believe a minor has given us data, write to us so that we can delete it.

Exchanges between your browser or the app, our servers and our providers are encrypted in transit (HTTPS). In the database, row-level security rules limit the reading of your practice data to your account; writes related to paid access are reserved to our servers, and the administration space is reserved to CertifBus administrators.

No system is infallible. In the event of a data breach likely to put you at risk, we comply with the notification obligations laid down by the GDPR.

We may change this policy, in particular to reflect a change in the service or in the regulations. The date of the last update appears at the top of the page; the version in force is the one published here. For an important change, we inform you where the law requires it.