Privacy notice
Last updated 18 August 2026
This explains what information Double Mark collects, why, and what your rights are — in plain English. Double Mark is a study tool that marks practice exam answers against published assessment objectives.
The short version
- We never store your written answers. The question and answer you submit are used only to produce your marking, then discarded.
- We never see your card details. Payments are handled entirely by Stripe.
- Make a personal account and we keep your email so you can sign in; use a school password and we keep only your first name — no email.
- No advertising or tracking cookies, and we never sell your data.
Who is responsible for your data
Double Mark is the data controller for the information described here. To ask a question or exercise your rights, contact DoubleMark.ai@outlook.com.
What we collect and why
If you create a personal account, we keep your email address (so you can sign in), your password in a securely scrambled (hashed) form that we cannot read, and a count of your free markings used and subscription status (so we know if you're on the free allowance or a paid plan).
If you sign in with a school password, we keep only your first name, so your teacher's dashboard can show usage. No email, and nothing else about you, is collected on this route.
When you mark an answer, the question and answer are sent to our marking provider, assessed, and the feedback returned to you. We do not store the question or answer text afterwards. We keep a record of numbers only about each marking — qualification, subject, exam board, the score, and the date — to run the free/paid allowance and the teacher dashboard. It never includes your written work.
Payments
Paid subscriptions are processed by Stripe, a certified payment provider. Your card details are entered on Stripe's own secure checkout and are never sent to or stored by Double Mark. We keep only a reference ID that confirms whether your subscription is active.
Companies that process data on our behalf
A few trusted providers help run the service, and only process your data to provide their part of it: Vercel (hosts the website), Supabase (stores account info — your email, hashed password and the numbers above), Stripe (payments), and Anthropic (the AI that marks your answer; the text you submit is processed to generate feedback and is not used to train their models).
Cookies
One essential cookie keeps you signed in. No advertising, analytics or tracking cookies — so no cookie banner to click through.
Age and younger students
Designed for students revising for exams, many under 18. Intended for ages 13 and over; under 13, a parent, guardian or teacher should set it up and agree on your behalf. The school route is deliberately minimal — a first name only.
How long we keep information
Written answers: not stored at all. Account details (email, hashed password, subscription status) and marking numbers: kept while your account exists, and deleted if you ask us to close it.
Changes to this notice
If we change how we handle data, we'll update this page and change the "last updated" date at the top.
Your rights
Under UK data protection law you can ask for a copy of the information we hold, ask us to correct or delete it, object to or restrict how we use it, and complain to the UK's Information Commissioner's Office (ICO) at ico.org.uk if you're unhappy. To exercise any of these, email DoubleMark.ai@outlook.com and we'll respond within one month.
Double Mark is a practice tool and is not affiliated with any exam board. See also our Terms of Use.