Privacy Policy

Last updated 8 November 2026

Bandwise is an online workspace that helps teachers assess their students’ practice work for English exams such as IELTS, Cambridge B2 First, C1 Advanced and C2 Proficiency, and the Michigan ECCE and ECPE. This policy explains what personal data Bandwise handles, why, and the choices you have.

1. Who is responsible

Bandwise is operated by Panagiotis Chatzigiannakis (“we”, “us”). Contact: hello@bandwiseapp.com.

We are the controller of teachers’ account data. For information about students that teachers add to Bandwise, the teacher (or their school) is the controller and we act as their processor: we handle it only to provide the service to that teacher and on their instructions. Our Data Processing Agreement sets out the terms for schools and teachers.

2. What we collect

Account data: your email address and, if you sign in with Google, your name and profile picture from your Google account.
Sign-in and security data: session records, one-time sign-in codes (kept for 10 minutes), and the IP address and browser type of each session, used to keep accounts secure and to limit abuse.
Content you add: students’ names, email addresses, target bands and test types; essays, photos, PDFs and speaking recordings; transcripts, scores, feedback and your notes; whether a piece of writing was done in class under supervision, and any comparison with a student’s class writing that you ask for (see section 5).
Settings: Email (SMTP) passwords you choose to save, which we encrypt before storing; your report branding, including any logo you upload.
Usage records: for each AI request, the provider, model, number of tokens used and an estimated cost; and how many Bandwise AI credits you have used this month.
About your teaching, if you tell us: your role, roughly how many students you teach, which exams, your country, how you heard about Bandwise and, optionally, the name of the person who recommended it to you.
How you found Bandwise: when you create an account, the campaign tags and any invite code in the link you followed (for example utm_source), whether you came from a Google or Meta ad (not the ad’s click ID), the website you came from (its domain only) and the first Bandwise page you opened.
Billing, if you buy a paid plan: Stripe, our payment provider, collects your payment details and billing details (for example your name, billing address and, for a business or school, a VAT number). We never see or store full card numbers. We keep your Stripe customer and subscription IDs, your plan and its status (for example active, cancelled or payment failed), and the amounts and dates of payments, refunds and credit pack purchases.
Feedback you give: if you answer our early-access surveys, your answers about pricing and time saved, how disappointed you’d be without Bandwise, which plan you’d choose, and its main benefit to you, and any comments, linked to your account.
Problem reports: if you use “Report a problem”, what you write, any screenshot you add, and technical details (the screen you were on, your browser, window size, language, time zone and any error messages showing). We use them only to fix problems, and delete a report’s screenshot once the problem is resolved.
Sales enquiries: if you use “Talk to us” on the pricing page, the name, work email, organisation, approximate number of teachers and message you enter, kept and emailed to our admins only so we can reply to you about a quote; we send you nothing else, and an enquiry is deleted on request.

3. Information from Google

If you choose “Continue with Google”, we ask Google only for your basic profile: your name, email address and profile picture (the openid, email and profile scopes). We use it solely to create your Bandwise account, sign you in and show your name in the app. We do not request access to your Gmail, Google Drive, contacts or any other Google data.

We do not sell Google user data, use it for advertising, or transfer it to others except as needed to run Bandwise (see section 6), for security, or where the law requires. Bandwise’s use and transfer of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements. We do not use Google user data to train AI models.

4. How we use data

To provide Bandwise: store your workspace, run the assessments you ask for, produce reports and send them when you choose.
To run your account: sign-in codes, approval of new accounts, and messages about your account.
To take payment for paid plans, keep track of your plan and credits, handle refunds and meet tax and accounting rules.
To keep the service secure and working, and to understand costs so we can price it fairly, including from survey answers you choose to give.
To see which channels bring teachers who find Bandwise useful, from how you found Bandwise (section 2), under our legitimate interest in understanding where our users come from.
To build a student’s writing profile from their supervised class writing, and to compare an essay with it when the teacher asks (see section 5).
To check how close AI estimates are to teachers’ own scores, using the bands on assessments teachers have reviewed, so we can improve accuracy; and, unless a teacher turns it off, to improve Bandwise AI’s marking for everyone from combined, anonymous figures about those scores (see section 5).

Our legal bases are performing our contract with you, our legitimate interest in running a secure and reliable service, and complying with legal obligations. We do not sell personal data, do not show advertising, and do not use your content to train AI models.

5. Writing profiles, comparisons, and learning from teachers’ scores

Teachers can mark a student’s writing as written in class, supervised. Bandwise then shows the teacher a writing profile of that student for that exam, built from those pieces only: plain measures of the text (length, words per sentence, share of long words and word variety), the average scores on them, and what their feedback said to work on. Bandwise’s own code calculates the profile when the teacher opens it. No AI is used, and the profile isn’t stored.

When a teacher asks, Bandwise can compare one essay written outside class with that student’s class writing. This sends the essay, the profile and up to four of the newest class pieces to Bandwise AI (see section 6). The result is stored with the essay: an overall comparison (consistent, some differences or very different), specific differences, each quoting both texts, and questions the teacher could ask the student about the essay. This is profiling of the student’s writing, which we carry out as the teacher’s processor, on the teacher’s instructions.

Only on request. A comparison runs only when a teacher asks for it, for one essay at a time. Nothing is compared automatically.
No automated decisions. A comparison never says whether a student used AI or anyone else’s help, and Bandwise makes no decision about the student. Differences can have many ordinary causes, such as more time, a dictionary, revising or real progress, and tools that claim to detect AI writing are unreliable, especially for learners of English. Any conclusion is the teacher’s, after talking with the student.
For the teacher only. Profiles and comparisons are shown only in the teacher’s studio. They are not included in reports, emails or anything students receive. A comparison is included when the teacher downloads their data.
Easy to remove. A comparison is deleted when the essay’s text changes, when the essay is marked as class writing, or when the assessment is deleted. Unticking “written in class, supervised” takes a piece out of the profile.
Transparency. Teachers who use these features should tell their students (and, for children, their parents or guardians) that their class writing may be used this way. A student can ask their teacher not to use it, or to delete a comparison.

Learning from teachers’ scores

When a teacher reviews Bandwise AI’s draft, their final scores show where they agree or disagree with it. We use those scores in three ways:

“Your marking”, for each teacher. A teacher can see, per task and criterion, how their own reviewed scores usually compare with Bandwise AI’s drafts. Only their own work is used, and only they see it.
“Adapt Bandwise AI’s drafts to my marking”, if a teacher turns it on. New drafts are moved by that teacher’s usual difference. Only their own work is used, each adjusted draft says so, and Bandwise AI’s own scores stay available.
Improving Bandwise AI for everyone. Where many teachers change Bandwise AI’s scores on a criterion in the same way, we may improve its marking instructions for everyone. For this we use only the scores: never students’ work, names or feedback. A difference is counted only when at least three teachers lean the same way, and what we look at is combined figures, which don’t identify any teacher, student or piece of work. A change is made only by us, only after testing it against examiner-marked official samples, and never automatically. Teachers can turn this off at any time under Settings → Your marking → Help improve Bandwise AI for everyone; their scores then stop counting.

Your school’s courses or custom exams, and marking

If Bandwise has switched these features on for a school, its school admins can also:

Keep a test bank and set up their courses or custom exams: the school’s own prompts, and exams with the school’s own tasks, criteria and rubric documents. These are the school’s content, stored for the school and used only for its teachers’ work.
Keep marked essays to teach Bandwise AI to mark like their teachers. These are essays with the teachers’ scores: ones the school imports, and copies teachers add from their own reviewed work. A copy leaves out the student’s name and the work’s title, but the essay itself is copied as written, so teachers should check it doesn’t name the student. Bandwise AI marks these essays to compare its scores with the teachers’ (a “check” or “try-out”), and the school can then use some of them as examples, a short written tip, or a fixed adjustment to Bandwise AI’s draft scores, for its own teachers only. When a school uses example essays, their text and scores are sent to Bandwise AI’s provider (see section 6) with each piece of that school’s work Bandwise AI marks. A school’s essays, tips and adjustments are never used for another school, or to improve Bandwise AI for everyone. Where we switch it on for a school, the same applies to speaking tests in the school’s courses or custom exams: a school admin can upload a recording of one student’s test with the teachers’ scores, or a teacher can add a copy of their own reviewed speaking test. The recording is copied as it is, so it holds the student’s voice and anything they say, which may identify them. Bandwise AI’s provider listens to it each time a check or try-out marks it; speaking tests are never used as examples.
See how their teachers mark. For each task, how each teacher’s reviewed scores usually compare with Bandwise AI’s drafts and with their colleagues’, by the teacher’s name, to help the school mark consistently. Each teacher is told so on their own “Your marking” page.
Let Bandwise help set them up. Only if a school admin turns this on, for 7 or 30 days, can Bandwise staff open the school’s courses or custom exams and its marking setup (its marked essays, checks, tips and examples), to draft and try them out with the school. They can’t start using anything or make an exam live, and they don’t see the school’s students, classes or teachers’ other work, though they see which of the school’s staff added each item and its marked essays (which may be copies of students’ essays). Everything they change is logged and shown to the school’s admins, and access ends by itself or when the school admin stops it.
Use one marking style for the whole school. If a school admin turns it on, Bandwise AI’s drafts for the school’s teachers are moved towards the school’s teachers’ usual marking, worked out from all of their reviewed work together. A teacher’s own adjustment, once ready, takes its place.

These features are part of the service we provide to the school as its processor (see section 1). Teachers’ final scores remain theirs: every adjusted draft says so, and Bandwise AI’s own scores stay available.

6. Who else handles data

Cloudflare hosts Bandwise and stores its database and files, and delivers Bandwise’s own emails (sign-in codes, account approval). It also delivers the progress reports and report links you email to students when you haven’t connected a mailbox of your own: the email carries your name, and a student’s reply goes to your email address.
Stripe processes payments for paid plans and credit packs, and holds your billing details, your subscription status and your invoices. Bandwise sends it what it needs to set up a purchase and receives your subscription status and payment results back. Stripe does not receive your students’ information or your content.
Google provides “Continue with Google” sign-in.
Cloudflare Web Analytics measures visits to our public pages without cookies and without identifying you. It isn’t used in the studio or on shared report links.
Bandwise AI receives the student work, prompt and rubric needed for a transcription or assessment, or the writing needed for a comparison with class writing, only when you request one. It is processed by Google Gemini under our account, on Google’s paid service, where Google does not use submitted content to improve its products or train its models. During early testing, Bandwise AI may instead run on Google’s free tier, where Google can use submitted content that way; while that is the case it is offered only to named testers, for sample work, and the studio says so. For writing, Bandwise AI may instead use, or fall back to, Luna, a model from OpenAI, under our account: it then receives the writing, prompt and rubric (and, for a transcription, the photo or PDF of the handwriting) through OpenAI’s API, which does not use submitted content to train its models; we ask OpenAI not to store it. Recordings of speaking always go to Google Gemini.
Your own email provider sends the progress reports you email to students, when you connect your mailbox.
Your browser’s speech service, when you use Read aloud. Bandwise reads the essay with your browser’s own voices and picks one on your device first, which keeps the text on your device. If you choose an online voice in Reading settings, or your browser has no voice on the device (for example some of Chrome’s “Google” voices), your browser sends the text being read to its maker, such as Google, to turn it into speech. Bandwise doesn’t send it there and gets nothing back. Read aloud uses no Bandwise AI.
Your students, when you share a report with one. A report link shows that one reviewed report to anyone who has the link, without signing in, until it expires (after 7, 30 or 90 days, as you choose) or you turn it off. Bandwise counts how often a link is opened and when it was last opened, and shows you that; it stores nothing about who opened it. Links are deleted with the work or your account.
Your school, if a school added you to Bandwise: its school admins can see your name, email and AI credit use, your students, and their assessments and feedback (read-only), add students to your classes, move classes and students between the school’s teachers, and set the branding on your reports. If the school uses the features in section 5, its school admins can also see, by your name, how your reviewed scores compare with Bandwise AI’s and your colleagues’, and the copies of your reviewed essays you add to its marked essays. The school is then the controller of its students’ information.

Some of these providers may process data outside the European Economic Area. Where they do, they rely on safeguards recognised under EU law, such as the European Commission’s Standard Contractual Clauses.

7. Where data is stored and how long we keep it

Bandwise’s database and files are stored with Cloudflare, currently in Eastern Europe. We keep account data while your account exists. Your content stays until you delete it or ask us to delete your account. Sign-in sessions expire after 30 days of inactivity, and sign-in codes after 10 minutes. When you delete your account yourself, its data is removed from Bandwise straight away. If you email us to close it, we do so within 30 days. Copies in our backups are deleted as the backups expire, within 90 days. We keep something only where the law requires it.

Billing records. If you bought a paid plan, Stripe keeps your customer record and invoices after your account is deleted, as tax and accounting law requires. We keep only records of payment events, with the links to you removed. Before we delete your account, we cancel any active subscription so you are not charged again.

Archived students. A teacher (or a school admin) can archive a student. An archived student stays listed and can be viewed, downloaded and restored. Three months after the student was archived, we plan to delete the student’s own records and files. We email the teacher (or the school’s admins) when the student is archived and again 30 and 7 days before the planned date, and we do not delete a student until the 7-day reminder has been sent, nor sooner than 7 days after it was sent. Restoring the student cancels the deletion. Deleting a student removes their own work, but not every copy: another student’s work that was shared with them (for example the other half of a paired speaking test) stays with that student’s work, and backups expire on their own schedule (see our Data Processing Agreement).

Students without new work. If a student has had no new work for 150 days, we archive the student and delete the files uploaded for their work (PDFs, recordings and Word files). Their scores, essay text, transcripts and feedback stay with the archived student, which then follows the rule above. We email the teacher (or the school’s admins) and show a notice in Bandwise 90, 30, 15 and 1 day before, and we never archive a student sooner than 90 days after the first of these notices appears in Bandwise. Giving the student new work starts the 150 days again.

A copy of a teacher’s essay or speaking recording in their school’s marked essays stays with the school when the teacher deletes the original work, for 90 days, and is then deleted (with its recording), unless the school has it in a set of example essays it uses or is trying out at that time (even if the feature is switched off for now); it is then kept while that set is, and deleted after that. A school admin can delete any of the school’s marked essays while the feature is switched on; while it is off, the school can download them with its data and ask us to delete them. Deleting the school deletes them all.

8. Students and children

Bandwise is for teachers, not for students to use directly. Teachers are responsible for having a lawful basis to add their students’ information and work, including consent from a parent or guardian where a student is a child and the law requires it. Teachers should add only what they need, and can edit or delete a student’s information at any time.

9. Security

All traffic is encrypted in transit. Saved AI keys and email passwords are encrypted at rest. Each teacher’s workspace is separate, and uploaded files are served only to their signed-in owner and, for a teacher in a school, to the school’s admins. The exceptions are report logos, which are publicly readable so that emailed reports can show them. No system is perfectly secure, but we work to protect your data and will tell you about any breach that affects you as the law requires.

10. Cookies

We use a sign-in cookie to keep you signed in. If you followed a link that shows how you found Bandwise, then when you start signing in or creating an account we also set one first-party cookie (bw_src) that carries this across the sign-in step. We use it only when your account is first created, delete it once you’re signed in, and it expires within one day at most. We set no cookies on our public pages. Cloudflare Web Analytics, which counts visits to them, uses no cookies. We use no advertising or cross-site tracking cookies, pixels or scripts.

11. Your rights

You can ask to access, correct, export or delete your personal data, to restrict or object to how we use it, and to withdraw any consent. You can download all your data, or delete your account and everything in it, yourself at any time under Settings → Account in the studio (a school admin can do the same for the whole school on the School page), or email hello@bandwiseapp.com. Deleting an account removes its students, their work and files, and its settings from Bandwise straight away (backup copies expire as section 7 describes); only anonymous counts of AI use are kept, for our cost records, together with the billing records described in section 7. Students whose information a teacher added should contact that teacher first; we will help the teacher respond. You can also complain to your data protection authority. In Greece, that is the Hellenic Data Protection Authority (dpa.gr).

12. Changes

If we change this policy, we will update the date above and, for significant changes, tell signed-up teachers by email before they take effect.