Privacy policy
Last updated: 8 November 2026 (age and consent at sign-up; feedback you send; analytics: our own anonymous counts only; counting each device once, the device email and the new-device limit); 2 November 2026 (AI marking: what is sent to Google's Gemini service); 20 October 2026 (answer timing, and how to turn it off; counting the devices a paid account is used on); 18 October 2026 (anonymous page counts, and the page an account was created from); 27 September 2026 (parent confirmation, no analytics, data sent outside India, how long we keep it)
In short: we store only what we need to run the account, show progress to the student, their parent and their teacher, and send the emails you asked for. We never sell data and we run no advertising.
1. Who runs this site
cbsemathrevision.com is one of the Math Revision sites run by Pete Bromfield (listed in the footer); they share one sign-in system and database. Questions about your data: pbromfield@ibmathrevision.com.
2. Children and parental consent
Most students are under 18. Students under 18 need a parent’s or guardian’s consent to use the site, or use it through their school, which signs up its students under its school agreement with us and gives any consent needed. We don’t ask your age at sign-up and there is no consent box there, so if you are under 18, ask a parent or guardian before you create an account. A parent or guardian sees a student's progress only through a link between their two accounts, and on this site every link needs the adult's own confirmation first: they sign in with the email address that was invited (the one-time code or sign-in link we email proves they own it) and tick “I am this student's parent or lawful guardian.” We record who confirmed, when, the version of the wording they saw and the statement itself. Until then the adult sees nothing about the student, and our invitation email does not name the student. A link can start in three ways: the parent asks and the student approves (the parent ticks a guardian statement when asking), the student invites the parent, or the student's school adds the parent. A link made without the statement is paused at the parent's next visit until they tick it.
Students see on their account page every adult who is linked to them or invited, and can stop a link they made at any time; for a parent their school added, they can ask their teacher or email us to remove it. A parent can withdraw consent at any time from the parent dashboard (Settings → Withdraw consent and close the link): the link closes at once, the weekly email about that child stops, and we record the withdrawal. That does not delete the student's own account: to have it deleted, email us from the parent's or the student's email address. There is no delete button yet; we do it by hand and reply within 30 days.
The weekly parent summary email is off until a parent turns it on in the parent dashboard (Settings). Before it starts, the dashboard says what the email contains, why we send it and how to stop it, and the parent confirms they are the student's parent or legal guardian; we record the date, that notice and the confirmation. It contains the child's name, their questions, time, sessions and last active day that week, tests and scores, chapters that are secure or need work, homework and one suggested next step; it has no advertising and is sent only to the parent's own email address, through our email provider (Resend). It stops when the parent unticks it in Settings or uses the one-click link at the bottom of any email (as easy as turning it on), and we record that too. The dashboard and the email also offer a “Share this summary on WhatsApp” link: it only opens WhatsApp on the parent's own phone with the text filled in, for the parent to choose whether and to whom to send it. The filled-in text uses the child's first name only (no email address or account link), and it passes to WhatsApp only if the parent taps the link. We do not use WhatsApp to send anything ourselves.
3. What we store, and why
| What | Why | Where |
|---|---|---|
| Email address (student and parent) | Sign-in, progress, and the emails you asked for (the Sunday report, homework notices). | Firebase Authentication (Google Cloud) |
| Practice answers, checkpoint results, timed test scores, homework and class membership | To show progress to the student, their linked parent and their teacher. | Firestore (Google Cloud) |
| Parent–student link and consent record | To prove consent and to decide who may see a student's progress. | Firestore |
| Your plan and payment records | Legal requirement to keep receipts. | Payment provider (card details never reach our servers) |
| School invoices (when a teacher asks us to invoice their school): the school’s legal name and billing address, the finance contact’s name and email, an optional copy-to email, the PO number and the school’s VAT number or GSTIN, if given | To send the invoice and payment reminders, show it to the school’s Heads of Department, and keep the accounting and tax records the law requires. | Firestore, and Stripe, which issues and emails the invoice. |
| Your devices: a random device ID your browser makes, a label such as “Chrome on Windows” (worked out from the browser’s user-agent, which we don’t keep), when each device was first and last used, and which of our four sites it was used on, and a scrambled code for the network it was used on | Accounts are personal and can be used on up to 5 devices; this is how we count them. To protect paid accounts, we also note how many different devices an account is used on, so we can spot a shared login. So that one phone or laptop counts once, we keep a scrambled code for the network each device was used on (made from the first part of its IP address, and different for every account); we never keep the IP address itself or your location. We keep an eye on account use: if we suspect an account is being shared, we may email you about it, and the account may be paused while we review it. Teacher, school and class accounts are not limited. You can see and remove your devices on your account page. No other fingerprinting. | Firestore; the device ID also sits in your browser’s local storage. A device unused for 60 days is deleted automatically. |
| Which page your account was created from: the page you first opened on this site in that browser tab, and the page the visit you signed up in started on (the page address only, never its query string), with where you came from (Google, another search engine, an AI assistant, another website by name, or directly) and any campaign tags in the link, and which of our sign-up buttons you tapped in that tab just before, if any (a short tag and its page) | We store which page an account was created on, to understand which pages help students. It is saved once, when the account is made, and never used for advertising. | Firestore, with your account. Before you sign up it is kept only in that browser tab’s session storage, which is cleared when you close the tab: no cookie, no ID, no IP address and no browser details. Nothing is kept if your browser sends Do Not Track or Global Privacy Control. |
| Feedback you send: the “Report a problem” form, “Was this useful?” thumbs and comments, and the “Feedback” link. We keep your message or rating, the page you were on, and your email address if you are signed in or give one | To fix problems, improve the site and reply to you. “Report a problem” messages are also emailed to us. | Firestore; “Report a problem” messages also reach our inbox through Resend. |
4. Who else processes data
- Google Firebase: sign-in, database, file storage, hosting and cloud functions.
- Stripe: plan payments (card and UPI details go straight to Stripe and never reach our servers), and the invoices schools ask for (it emails them to the school’s finance contact).
- Resend: transactional email.
- Emergent (emergentagent.com): storage for some uploaded files, such as class handouts and photos of written homework.
- Your teacher: if a student joins a class, the teacher sees their progress for that class.
- AI marking (Google Gemini): when you ask for your written working to be marked, the question and your answer (or a photo of your working) are sent to Google's Gemini service to mark it and write the feedback. We don't use them to identify you. No other AI feature runs on this site.
No advertising networks, no analytics services, no tracking pixels, no profiling, no selling of data. This site does not load Google Analytics, the chat widget used on our other sites, or any other tracker. To keep the site working we load one set of files from another provider's servers, which then sees your IP address as any website does: the Firebase code from Google (sign-in and saving your work). Everything else (code libraries for maths display and PDFs, and fonts) is served from this site. If you are a teacher and a class QR code can't be drawn in your browser, the class join link is sent to a free QR-code service (api.qrserver.com) to draw it.
5. Data sent outside India
Some of the companies that run parts of this site store or process data outside India:
- Google (Firebase): sign-in, database, file storage, hosting and our server code. Our server code runs in Google's
us-central1region in the United States, with a few older functions ineurope-west1(Belgium); other Firebase services may keep data in the United States or other Google locations. - Stripe: payments, processed in the United States and other countries.
- Resend: a US company that delivers our emails, so email addresses and the emails themselves are processed in the United States.
- Emergent (emergentagent.com): storage for some uploaded files; its servers may be outside India.
- Google (Gemini API): AI marking of written working, only when you ask for it (see section 4), which may be processed in the United States or other countries.
The site is run from the United Kingdom, so Pete Bromfield also handles data from the UK. How we protect it: each provider gets only what it needs for its job; every connection to them is encrypted (HTTPS); card and UPI details go straight to Stripe and never reach our servers. We use each provider under the terms it offers its customers, and each publishes its own privacy terms. If you'd like to know more about a transfer, email us.
6. Cookies and local storage
Analytics on this site: our own anonymous, first-party counts only. No third-party analytics. We use only essential cookies, and browser storage only as described here, so there is nothing to accept or refuse: a small notice says so on your first visit. Sign-in storage keeps you signed in. Local storage remembers small preferences on your device (for example that you have seen that notice), and a random device ID that counts this browser as one of your (up to 5) devices — sent to us only while you’re signed in. Session storage in the browser tab notes the page you arrived on, for the account record in section 3, until you close the tab. We count anonymous page steps (for example “opened the plans page”) as daily totals on our own servers, with no cookie or ID (your IP address is not stored). We also count page views and how the site is used, the same way as on our other sites: each page view (with only whether you came from Google, Bing, another search engine, social media, another website, another of our pages or directly), the kind of link or button clicked, how far long pages are scrolled, the page a visit left from, page speed, and errors or missing pages. These are anonymous daily counts on our own servers: no cookies, no ID, no IP address, no browser details and no personal data are stored, and we don’t try to tell visitors apart. Nothing is counted if your browser sends Do Not Track or Global Privacy Control. If the page you are on has campaign tags in its address (e.g. a link in a newsletter) and you sign up for emails on that page, those tags are saved with your sign-up.
Help improve the site: answer timing
When you answer practice questions while signed in, we note how long you take before your first answer, whether you change your answer and how often you switch between multiple-choice options. We use this only to personalise your practice. It is on unless you turn it off. To turn it off: use this switch for this browser (it is saved in this browser’s local storage), or email pbromfield@ibmathrevision.com and we will turn it off for your account on every device.
7. How long we keep it
- Account and progress data: while the account is in use, or until you ask us to delete it. We review accounts by hand every three months: a student account on this site that nobody has signed in to for 24 months gets an email saying it will be deleted, and is deleted 30 days later unless someone signs in.
- Consent records (the parent link and guardian statement, and the weekly summary: when consent was given or withdrawn, and the wording shown): kept while the link exists and for 12 months after it ends, so we can show what was agreed; we remove older ones in the same three-monthly review. We keep the last 50 link events and the last 20 weekly-summary changes for each parent.
- Payment records: as long as tax rules require.
- School invoice details: as long as needed for accounting and tax records.
8. Your rights and grievances
Under India's Digital Personal Data Protection Act, 2023 (and UK GDPR, where it applies) you can ask for a summary of your data, a correction, deletion, or to withdraw consent, and nominate someone to act for you. A parent acts for a child under 18.
Grievances and questions about your data: email pbromfield@ibmathrevision.com, read by our team. We respond within 30 days. You can stop the weekly summary yourself at any time (Settings in the parent dashboard, or the link in any email) and remove a child from your dashboard there too. If you are not satisfied with our answer, you can complain to the Data Protection Board of India.