Privacy notice

Who we are

Paper Zero is run by Prepalio International B.V. (KvK 42134936), Honingerdijk 85A01, 3063 AK Rotterdam, the Netherlands, which decides how your data is used. If you have a question or a request about your data, email contact@paperzero.app.

What we keep, and why

• Your account. To try a question you need nothing: we create a guest account so your answers are kept. If you save your progress, we keep your email address to send you sign-in codes.
• Your profile, one answer at a time, each with a way to say no: your maths course, your exam session, whether you are 16 or older, your first name, your school, your maths teacher's name if you have no class code, and your target grade. We use them to plan your practice, to name you in a parent's report or a teacher's class, and to see which courses, schools and teachers ask for Paper Zero. Your teacher's name is seen only by us. When you look for your school, we list schools in the country your connection comes from first; we use that country for the search and don't keep it.
• Your answers: what you type, write or photograph, how it was marked, the help you used, and when. Handwritten answers are kept as the pen strokes, and photographs of paper as the picture, so we can show you your page again. We use your answers to mark them, show your progress, estimate your exam score, and make marking better.
• What your class has covered, by topic: from your textbook and chapter, from your own ticks, from your teacher's class, or worked out from what you already do well. Your plan practises what's covered and holds back what isn't.
• Your school exams: the dates of tests and mock exams, the results you enter, and the pages of a marked paper you choose to upload. See “School exams and uploaded pages”.
• Your choices: what you, or a parent for you, agreed to, with the exact words shown and when; and which questions about your profile you were asked, so you aren't asked twice.
• Messages you send us: when you tap “Message a person”, we keep the type you picked, your line, which question you were on, your answer if it was marked, and the page as it was on your screen, with our reply. When you report a problem, we also keep the page you were on and basic details of your device and browser. People who run Paper Zero read every message, to help you and to fix the app and the marking. A message is kept with your account and goes when your account goes.
• How you use the app. Which screens you open, which sections of the textbook column you read, when you switch between writing, typing and a photo, and when you use a picture or a graph, each as a short code with the time, so we can see what helps and what gets in the way. These records carry your account's id and nothing that names you: no email address, no name and nothing you wrote. They go with your sign-in session, not with a cookie, and we delete them after 12 months. PostHog also counts the pages you open and these same records, so we can see where people get stuck. It knows a signed-in account by its id only, and a visitor by a random number kept in the open tab, which goes when you close it.
• Technical data. The services that run Paper Zero log requests, including IP addresses, to keep it working and secure.

Marking your handwriting, and photos of paper

When you check a handwritten page, or a photograph of a page you wrote on paper, we send the picture, with the question and its mark scheme, to Anthropic. Anthropic's AI model reads your working, marks it and writes the feedback on your page. We ask you before the first time.

Anthropic processes your page for us under its commercial terms, which say it doesn't use it to train its models. Anthropic is in the United States. Photographs are stored in a private space that only you and our server can read. You can type your answers instead at any time.

Classes, and what a teacher sees

A teacher at your school can make a class with a code. If you join it, you share with that teacher how many days you practised each week and how many questions and pages you had marked, and we keep the words you agreed to. Pooled with the rest of the class, your answers also show the teacher which question types and which marks the class finds hardest, beside what the class has covered and its next exam. The teacher also sets what the class has covered and the dates of its tests, which your plan reads.

Your teacher never sees your pages or your working: not your written pages, your photographs, your answers to individual questions, your predicted score or your parent's details. You can leave the class at any time from your classes page, and you disappear from the teacher's view when you do. A parent can ask us to remove you by emailing contact@paperzero.app.

Teachers sign in with a school email address, which we keep with their school, and agree to our teacher terms.

School exams and uploaded pages

You can set the date of a school test or mock exam, or see the one your class's teacher set, and enter your result. If you upload photographs of your marked paper, we store them in the same private space as photos of practice, and use them to show you where you lost marks, by question type. We ask you, per upload, whether we may also keep the pages to check our own marking against your teacher's. Without that tick the pages serve only your breakdown.

A teacher who set the exam sees your result; never your pages.

Emails to a parent

If you invite a parent, we keep their email address and send them one email to confirm. Only if they confirm do they get a weekly email: how much you practised, your predicted score and the topics to work on, with one line about IB Math Lab, an IB Maths course. A parent who agreed to it also gets a short note around a school test or mock exam: ten days before, with the topics it covers and where you stand, and when you enter the result. We keep what they agreed to and when, and we log each email we send.

They can unsubscribe from any email with one click, and you can stop it from your account at any time. We count clicks on the IB Math Lab line, and nothing else about the email.

Paying for the plan

If you, or a parent, pay for Paper Zero Pro, Stripe handles the payment. Stripe receives the payer's name, email address, billing address and card or bank details; we never see or keep card or bank numbers. We keep which account the plan is for, who paid (you or a parent), the plan's status and dates, and Stripe's reference numbers for the customer and the subscription. Stripe also works out the VAT from the billing address.

When you send a parent a link to pay, the parent's page shows your first name and the plan. If the parent gives their email on that page, we keep it with the link, even if they don't pay, so the payment can be finished and so we can answer questions about it. We email them news only if they tick that box, which starts unticked.

Earning days of Pro

When you earn days of Pro, we keep a record of each reward: which task, when, how many days, and the id of what showed it was done (for example the class you joined or the test you uploaded). We use it to give the days, to make sure each task pays once, and to count how students find Paper Zero. The legal basis is our contract with you: the days are part of the service. The tasks only use what you already give us for their own purpose; a reward never depends on agreeing to research use of your pages or to emails.

Your invite link carries a code that is yours. When a friend signs up with it, we record that they came through your link and when they marked their first page, so both of you get your days. We never ask for a friend's email or number, and you see only how many friends joined, never who. The same holds for the link you send a teacher: we record which teacher came through it.

If a friend tries a question as a guest first, we record at that moment that they came through your link, so it still counts if they save their account within 30 days.

We keep these records while your account exists, and delete them with it. We also note when a suggestion was shown to you or put off with "Not now", so it isn't shown again too soon.

If you are under 16

We ask whether you are 16 or older. Under 16, a parent agrees for you to the two things that share your data further: joining a teacher's class, and uploading photographs of your marked school exams. The parent you invite for the weekly emails does this on the page where they confirm, each as a separate choice, and we record that it was the parent who agreed. Until they have, you can't join a class or upload exam pages. Ask a parent or guardian before you agree to handwriting marking, too.

Who helps us

These companies process data for us, under data processing agreements, and only to run Paper Zero:

• Supabase: our database, file storage and sign-in, in Frankfurt, Germany.
• Vercel: hosts the app; our server code runs in Frankfurt.
• Resend: sends sign-in codes and the emails to parents, from Ireland.
• Anthropic: marks handwritten and photographed answers and writes their feedback, in the United States.
• Cloudflare: checks that a sign-in comes from a person, not a bot.
• PostHog: counts how the app is used, in Frankfurt, Germany.
• Stripe: takes payments for the plan and works out the VAT, in Ireland (Stripe Payments Europe) and the United States.

When data goes to the United States, the safeguards in these companies' data processing terms apply. We don't sell your data, and we don't use it for advertising.

Cookies and your device

We use two kinds of cookie: the one that keeps you signed in, and, when you try a question through a friend's invite link, one that keeps their invite code for up to 30 days, so the reward still counts if you save your account later. We use no advertising or analytics cookies. Your browser also keeps some things on your device: answers and pages you haven't checked yet, and your settings, such as Write or Type and where the question card sits.

How long we keep it

We keep your account, your answers and your uploaded pages until you ask us to delete them. The services above keep their logs for a limited time.

Records of payments and invoices are kept for 7 years, because Dutch tax law requires it, even if the account is deleted.

The legal basis

• Running the practice you asked for: your account, your profile, your answers and their marks, your exam dates and results.
• Your consent: handwriting and photo marking, sharing your progress with a teacher, keeping exam pages to check our marking. You can withdraw each by telling us; withdrawing doesn't undo what was done before.
• A parent's consent: their emails, and, under 16, the sharing and the uploads above. They can unsubscribe from any email, and ask us to stop the sharing.
• A teacher's agreement to the teacher terms, for the class view.
• The contract with the payer, for the plan and its payments; and our legal duty to keep tax records.
• Our legitimate interest in keeping Paper Zero secure and making marking better.

Your rights

You can ask to see the data we keep about you, correct it, delete it, limit or object to how we use it, or get a copy to take elsewhere. Email us and we'll answer within a month. If you're not happy with our answer, you can complain to the Dutch data protection authority, the Autoriteit Persoonsgegevens.

Changes

When this notice changes, we update it here with a new version and date. Version 3 added classes and teachers, school exams and uploaded pages, photos of paper, the notes to parents around an exam, and the rules for students under 16. Version 4 added the messages you send us from a question or a marked page. Version 5 added paying for the plan through Stripe, and the page a parent pays on. Version 6 added your maths teacher's name and the country used to order the school search. Version 7 added earning days of Pro: the record of each reward and the invite links for a friend or a teacher. Version 9 keeps a friend's invite code for up to 30 days, so a reward still counts if you save your account later. Version 10 added reporting a problem from any page. Version 11 added PostHog, which counts how the app is used.