certifyboost

Joint Controller Arrangement (Annex B)

Version 2026-10-06 · Effective 6 October 2026

Contents
  1. About this document
  2. 1. Joint control and its limits
  3. 2. The Shared Progress Data
  4. 3. Purposes and legal bases
  5. 4. Responsibilities
  6. 5. Information to Students and parents
  7. 6. Minimum Age
  8. 7. Requests from Students and parents
  9. 8. Personal data breaches
  10. 9. Retention
  11. 10. Liability
  12. 11. The essence of the arrangement
  13. 12. Duration, changes and law

In short (not part of the Annex). When the School's Owners and Teachers see a Student's progress in the Classroom, that data comes from the Student's own Learner Account. The School and ntagks decide together that it is shown, so they are joint controllers for it (Article 26 GDPR). The School is responsible for its legal basis, for informing Students and parents, and for inviting only Students of the Minimum Age. ntagks is responsible for the platform, its security and what it shows, and is the contact point for requests. Students can use their rights with either party.

About this document

  1. Purpose. This Annex is the arrangement required by Article 26(1) GDPR between the School and ntagks. It covers the processing that they determine together: the Classroom showing data from Students' Learner Accounts to the School's Owners and Teachers (the Shared Progress Data). It sets out each party's responsibilities towards Students, parents and supervisory authorities.
  1. Parties and terms. The parties are the School and ntagks, as identified in the School Agreement and in Annex I of the DPA. Capitalised terms have the meaning given in the School Agreement and in the DPA (Annex A).
  1. Place in the Agreement. This Annex forms part of the School Agreement. For Shared Progress Data it prevails over the rest of the School Agreement (clause 3.2). It does not change Annex A, which governs Classroom Data, or the Privacy Policy, which governs each person's Learner Account. Nothing in this Annex limits the rights of data subjects.

1. Joint control and its limits

1.1 Three roles. Under clause 18.1 of the School Agreement:

  • (a) for Classroom Data, the School is the controller and ntagks its processor (Annex A);
  • (b) for each person's Learner Account, ntagks is an independent controller (Privacy Policy);
  • (c) for the Shared Progress Data, the School and ntagks are joint controllers (this Annex).

1.2 Why the control is joint. The purposes and the essential means of the processing in clause 1.1(c) are determined by both parties:

  • the School decides to use the Classroom, which Students to invite, which classes to form, which work to assign, and which persons have Owner or Teacher access, and it uses what they see for its teaching;
  • ntagks decides which Learner Account data the Classroom shows, how that data is computed and presented, and how the platform is secured. The data comes from Learner Accounts that ntagks controls.

1.3 Limits. Joint control covers only the operations in clause 2: retrieving the Shared Progress Data from the Learner Account and showing it to the School's Owners and Teachers in the App. It does not cover:

  • (a) anything before that point, which is the processing of the Learner Account by ntagks as independent controller (for example scoring an essay or counting XP);
  • (b) anything after that point. If an Owner or Teacher copies Shared Progress Data out of the App (for example in notes, a screenshot, a printout or the School's own systems), the School is the sole controller of that copy.

2. The Shared Progress Data

2.1 What the Classroom shows. The Owners of the School Account can see the following data from the Learner Accounts of its Students, for all classes; each Teacher sees it only for the classes an Owner has put them on:

Where in the ClassroomWho sees itData from the Student's Learner Account
Every list that names a Student (Students, Classes, Assignments and, for Owners, Plan & Billing)Owners and TeachersThe Student's display name: the full name set in the Learner Account, or the username if no full name is set
Progress page of a course assignment, and the Student's pageOwners and TeachersFor each assigned Student: the number of lessons and exercises completed in the assigned course or chapters (including any the Student completed before the assignment was set), out of the total, and that number as a percentage; and the average percentage of the assigned Students
Progress page of a mock-exam assignment, and the Student's pageOwners and TeachersFor each assigned Student, about their most recent attempt at the assigned mock exam that they started after they were given the assignment and after they joined the School Account (earlier attempts are never shown): its status, in the same words the Student sees (not started; in progress; grading, while the AI is still grading a writing or speaking section of a completed attempt; or finished); once it is finished, the overall score, marked "AI" because it includes AI-graded writing or speaking, and whether that score reaches the pass mark ("Passed" or "Failed"), or "Provisional" while a writing or speaking section is still ungraded; and the average of the finished scores, labelled "AI estimate"
Page of a classOwners and TeachersFor each active Student in the class: their rank in the class and their XP for the current week (from Monday 00:00 UTC), counting all XP the Student earned anywhere in certifyboost. A Student who has hidden themselves from rankings is listed without rank or XP
Plan & Billing, Live Interview minutes, and the Student's pageOwners onlyThe Live Interview Minutes that this School granted to each active Student, with the date of each grant, and how many of them are left: the Student's remaining balance, but never more than the minutes this School granted. Minutes the Student bought or received elsewhere are not shown

2.2 What the Classroom never shows. Owners and Teachers cannot see, through the Classroom or any other function of the Service:

  • Students' essays, speaking recordings, transcripts or answers to individual questions;
  • the text of AI feedback;
  • section scores;
  • mock exams and courses that the School has not assigned, practice drills, boosters, flashcards, the mistakes review and statistics;
  • date of birth, country, target exam, goal date, sign-in activity and payment details.

The only exception is a review that a Student asks for (clause 2.6). The Classroom has no function to export Shared Progress Data.

2.3 No separate copy. The App does not store Shared Progress Data as Classroom Data. It computes it from the Learner Account each time an Owner or Teacher opens a view. The source data stays in the Learner Account and is governed by the Privacy Policy.

2.4 When the data is visible. A Student's Shared Progress Data is visible only while:

  • (a) the Student is an active member of the School Account;
  • (b) the School Account is active (the Owners of a suspended School Account see only Plan & Billing, clause 14.2 of the School Agreement); and
  • (c) for assignment progress, the Student is assigned to that assignment.

It stops being visible when the Student leaves or is removed, when the Student asks to delete their Learner Account, when the School Account is suspended, and when the Agreement ends.

2.5 Classmates. Separately from the Shared Progress Data, each Student sees on the Class tab of their leaderboards a weekly XP ranking of their class or, for a Student who is in no class, of all active Students of the School. There, classmates appear only under their random two-word handle with an avatar generated from it, never with their name, and each Student sees their own row as "You". The School's only part in this board is forming the classes. ntagks provides it as independent controller under its Privacy Policy, like its other leaderboards, and every Student can hide themselves from it in their settings.

2.6 Reviews asked for by a Student. A Student can ask their Teachers to review an AI writing or speaking score, or a Live Interview score, with the "Ask your teacher to review" button under the score. For that one score, the Teachers of the Student's class (the Owners, for a Student who is in no class) see the piece of work (the essay, the speaking recordings with their transcripts, or the Live Interview transcript), its AI score and its AI feedback, and record their answer, which the Student sees in the App. The request and the answer are Classroom Data: the School carries out the review as controller and ntagks processes it on the School's behalf under the DPA (Annex II, "Review requests"). The material stays in the Learner Account; the Classroom shows it only for an open or answered request, and only while the Student is an active member (clause 2.4).

3.1 Joint purposes. The parties process Shared Progress Data jointly only to:

  • (a) let the School's Teachers follow how Students are getting on with the work they assigned, so that they can decide what to teach and practise next;
  • (b) let Teachers see, per class, how much Students practise each week, to encourage them;
  • (c) let Owners see which Students have Live Interview Minutes left when deciding to whom to give more.

3.2 No other purpose. Neither party uses Shared Progress Data for any other purpose. In particular:

  • the School must not use it as, or as part of, a grade or other formal assessment, or for any decision about a Student (clause 16 of the School Agreement), or to monitor Students' behaviour (clause 15.1(g));
  • ntagks does not use a Student's membership of the School, or the School's view of the Student's data, for advertising, sale or profiling for any purpose other than the Service.

3.3 Legal bases. Each party is responsible for having its own legal basis under Article 6 GDPR for its part of the processing:

  • (a) The School relies on the basis that fits its situation, for example: performance of its contract with the Student, or with the parents, for the Student's tuition (Article 6(1)(b)); a task carried out in the public interest or in the exercise of official authority under its national education law (Article 6(1)(e)), for public schools; or its legitimate interest in organising teaching (Article 6(1)(f)). The School states its basis in the information it gives under clause 5.
  • (b) ntagks relies on performance of its contract with the Student (Article 6(1)(b)). A Student who accepts a School's invitation, or signs up with the e-mail address the School invited, connects their Learner Account to the School Account, and showing their progress to the School's Owners and Teachers is how that connection works. For Students under 18, ntagks relies on the same basis as for the rest of their Learner Account, which is the Student's own consent (Privacy Policy §2).

4. Responsibilities

4.1 Overview.

TopicThe Schoolntagks
Legal basis (Article 6)For its part (clause 3.3(a))For its part (clause 3.3(b))
Information to Students and parents (Articles 13 and 14)Before inviting: its notice, with the essence of this Annex (clause 5.1, Annex C)Privacy Policy §6 and the invitation (clause 5.2)
Minimum AgeInvites only Students who meet it (clause 6)Checks it when a Learner Account is created (clause 6)
Who can see the dataGives Owner and Teacher access only to staff who need it, and asks for removalsAuthorises every Classroom request on the server
Security (Article 32)Its staff's accounts and devices, and any copiesThe platform (Annex III of the DPA)
Data protection by design and by default (Article 25)Uses only what it needsShows only the data in clause 2.1
Requests from data subjectsAbout its own use and its copies (clause 7.3)Contact point; requests about the data in the App (clauses 7.1 and 7.2)
Personal data breachesBreaches on its side (clause 8.3)Breaches in the platform (clause 8.2)
Records and DPIA (Articles 30 and 35)Its ownIts own

4.2 The School is responsible for:

  • (a) its legal basis (clause 3.3(a));
  • (b) informing Students and parents before inviting them (clause 5.1);
  • (c) inviting only Students who meet the Minimum Age (clause 6);
  • (d) inviting only Students who are enrolled with it, at correct e-mail addresses, and placing them in the right classes;
  • (e) giving Owner and Teacher access only to staff who need it for teaching, asking ntagks promptly to remove anyone who leaves the School or no longer needs access (clause 5.3 of the School Agreement), and making sure that its Owners and Teachers keep their Learner Accounts secure (clause 15.1(h));
  • (f) using Shared Progress Data only for the purposes in clause 3.1, and keeping any copy under clause 1.3(b) secure and no longer than needed for those purposes;
  • (g) removing a Student from the School Account when the Student leaves the School or the course, or asks to leave (clause 6.6 of the School Agreement);
  • (h) any data protection impact assessment it must carry out, and its own records of processing;
  • (i) handling the requests in clause 7.3;
  • (j) answering its Students' review requests (clause 2.6) within a reasonable time, through Teachers who use the material only for that review.

4.3 ntagks is responsible for:

  • (a) its legal basis (clause 3.3(b));
  • (b) the security of the platform: the measures in Annex III of the DPA apply to Shared Progress Data as they apply to Classroom Data, including the server-side check, on every Classroom request, that the person is an active Owner or Teacher of the School named in the request;
  • (c) data protection by design and by default in the Classroom: showing only the data in clause 2.1 and never the data in clause 2.2, marking scores that include AI grading with "AI" and the notice in clause 16.3 of the School Agreement, showing classmates only pseudonymous handles, and letting every Student hide themselves from rankings;
  • (d) computing the Shared Progress Data correctly from the Learner Account, and offering Students a way to ask their Teachers to review any AI writing or speaking score (clause 2.6);
  • (e) informing Students about its own processing (clause 5.2);
  • (f) acting as the contact point and handling the requests in clauses 7.1 and 7.2;
  • (g) leading on breaches in the platform (clause 8.2);
  • (h) giving the School the information it needs for its own information duties, DPIA and records: this Annex, Annexes II to IV of the DPA, the Privacy Policy and the template in Annex C, and answering the School's reasonable questions.

4.4 Both parties must:

  • (a) cooperate in good faith and give each other, without undue delay, the information each needs to comply with the GDPR for the Shared Progress Data;
  • (b) tell each other without undue delay of any complaint, inquiry or order of a supervisory authority or court about Shared Progress Data, and coordinate their answers where both are concerned;
  • (c) be able to demonstrate their own compliance, and make this Annex available to a supervisory authority on request.

5. Information to Students and parents

5.1 By the School. Before inviting a Student, the School gives the Student and, for a Student under 18, the parents or guardians the information required by Articles 13 and 14 GDPR for the School's part, including the essence of this arrangement (clause 11). The School may use the template in Annex C. It keeps a record that it gave the information (clause 17.3 of the School Agreement).

5.2 By ntagks. ntagks informs Students about its own processing in its Privacy Policy, whose section 6 describes the Shared Progress Data, the three roles and the essence of this arrangement, and in the invitation, which tells the Student what the School will be able to see and links to that section (clause 17.4 of the School Agreement). ntagks keeps section 6 consistent with this Annex.

6. Minimum Age

6.1 The School must not invite any person below the Minimum Age (clause 17.1 of the School Agreement). When creating a Learner Account, the App asks for the date of birth and country and refuses anyone below the Minimum Age.

6.2 If either party learns that a member of the School Account is below the Minimum Age, it tells the other at once. The School removes the person from the School Account, and ntagks handles the Learner Account under its Terms of Service and Privacy Policy.

6.3 The School cannot give consent on behalf of a parent and is not asked to (clause 17.2 of the School Agreement).

7. Requests from Students and parents

7.1 Contact point. ntagks is the contact point for data subjects for the Shared Progress Data (Article 26(1) GDPR), at hello@certifyboost.com. Both parties name this contact point in the information they give. This does not prevent a data subject from exercising their rights against the School or against ntagks (Article 26(3) GDPR).

7.2 Requests that ntagks handles. ntagks handles requests about the Shared Progress Data in the App and the Learner Account data it comes from. In particular:

  • (a) access: ntagks gives the Student a copy of their Learner Account data, and tells them which of it the School can see (clause 2.1);
  • (b) rectification: the Student can correct their name in their settings; for an AI score, the Student can ask their Teachers to review it (clause 2.6);
  • (c) objection and restriction: ntagks explains the Student's options: hiding from rankings in their settings, which takes effect at once; or leaving the School Account, in which case ntagks removes the Student and tells the School (clause 6.6 of the School Agreement);
  • (d) erasure: the Student can delete their Learner Account in their settings, which ends the visibility (clause 2.4) and deletes their Classroom Data (Part 2, B5.2(a) of the DPA).

Where a request requires a decision or action by the School, or concerns the School's use of the data (for example a complaint about how a Teacher used it), ntagks forwards it to the School within 3 Business Days and the parties coordinate the reply.

7.3 Requests that the School handles. The School handles requests about its own use of the Shared Progress Data: its decision to use the Classroom, its legal basis, how its Owners and Teachers use what they see, and copies it holds under clause 1.3(b). If the School receives a request about data in the App, it forwards it to ntagks within 3 Business Days, or answers it with information that ntagks provides within 5 Business Days of being asked.

7.4 Requests that also concern Classroom Data are handled, for that data, under Part 2, B5 of the DPA, where the School decides and ntagks assists. The parties coordinate so that the person receives one consistent answer where possible.

7.5 Parents and guardians. A party that receives a request from a parent or guardian on behalf of a Student checks, in a proportionate way, that the requester has parental responsibility, and tells the other party where the request concerns it.

7.6 Deadlines and records. The party that answers does so within one month of receipt by either party (Article 12(3) GDPR); forwarding must not make the answer late. Each party keeps a record of the requests it handles. Neither party charges the other for this cooperation.

8. Personal data breaches

8.1 Notice to each other. Each party tells the other without undue delay, and in any event within 48 hours, after becoming aware of a personal data breach affecting Shared Progress Data, with the information listed in Article 33(3) GDPR that is available at the time, and updates it as more becomes known. ntagks notifies every Owner and the contact in Annex I of the DPA; the School notifies hello@certifyboost.com.

8.2 Breaches in the platform. For a breach in ntagks's systems or those of its providers (for example a flaw that lets someone outside the School see Shared Progress Data), ntagks:

  • (a) contains and investigates the breach;
  • (b) assesses the risk to Students, consulting the School;
  • (c) notifies the competent supervisory authority where Article 33 GDPR requires it, within 72 hours of becoming aware, naming both parties;
  • (d) informs the affected Students where Article 34 GDPR requires it, and gives the School a text that it can use to inform Students and parents;
  • (e) documents the breach (Article 33(5) GDPR) and gives the School a copy of the record.

8.3 Breaches on the School's side. For a breach that arises from the School, its Owners or Teachers, or their accounts, devices or copies (for example a Teacher's account taken over through a shared password, a printed list that is lost, or a Teacher's misuse of the data), the School assesses the risk and makes the notifications and communications required by Articles 33 and 34 GDPR. ntagks assists, for example by suspending the access of the Owner or Teacher concerned and by providing the information it holds.

8.4 Unclear cause. Where the cause is unclear or lies with both parties, they agree promptly who notifies. If they have not agreed in time, ntagks notifies the supervisory authority so that the 72-hour deadline is met, and the School informs Students and parents using ntagks's text.

8.5 Other data. Where the same incident also affects Classroom Data, Part 2, B4 of the DPA applies to that data. Where it affects Learner Account data beyond the Shared Progress Data, ntagks acts as controller (Part 2, B4.4 of the DPA).

9. Retention

9.1 Shared Progress Data has no retention period of its own because it is not stored separately (clause 2.3). The source data is kept and deleted under the Privacy Policy. Classroom Data is kept and deleted under Part 2, B8 of the DPA.

9.2 The School keeps any copy under clause 1.3(b) under its own retention rules, and no longer than needed for the purposes in clause 3.1.

10. Liability

10.1 Towards data subjects, each party is liable as Article 82 GDPR provides. Nothing in this Annex limits that liability.

10.2 Between the parties, a party that has paid full compensation to a data subject under Article 82(4) GDPR may claim back from the other party the part of the compensation that corresponds to the other party's part of the responsibility for the damage (Article 82(5) GDPR).

10.3 Each party bears any administrative fine imposed on it. Otherwise, clause 24 of the School Agreement applies.

11. The essence of the arrangement

11.1 Under Article 26(2) GDPR, the essence of this arrangement must be made available to data subjects. Both parties use the following text:

Your school and certifyboost: who is responsible for what. When your school uses certifyboost, your teachers can see part of your progress from your own certifyboost account: your name, your progress on the work they assign, the status, score and pass/fail result of assigned mock exams (scores marked "AI" are practice estimates, not grades), and your weekly XP in your class. The school's account owners also see the Live Interview minutes the school gave you and how many of them are left. Teachers never see your essays, your recordings or your AI feedback, unless you ask them to review a score, and your classmates see you only under a random two-word name. Your school and certifyboost (ntagks, Greece) are responsible for this together, as "joint controllers" (Article 26 GDPR). Your school decides to use certifyboost, must have a legal reason for it, must tell you and your parents about it, and may only invite students who are old enough. certifyboost runs the platform, keeps it secure, decides what teachers can see and handles requests about the data in it. You can use your data protection rights with either of us. The easiest way is to write to hello@certifyboost.com; if you contact your school, it passes your request on where needed.

11.2 The School includes this text in the information it gives under clause 5.1 (Annex C contains it). ntagks publishes it, or a version with the same content, in section 6 of its Privacy Policy, and provides this Annex to any data subject on request.

12. Duration, changes and law

12.1 This Annex applies for as long as the School's Owners and Teachers can see Shared Progress Data. Clauses 7, 8 and 10 continue to apply after it ends to matters that arose before.

12.2 Changes follow clause 29 of the School Agreement. If ntagks changes the Learner Account data that the Classroom shows, it updates clause 2.1 and section 6 of its Privacy Policy. A change that shows more data takes effect no earlier than 30 days after ntagks tells the Owners, so that the School can update the information it gives. A change that shows less data may take effect at once.

12.3 This Annex is governed by Greek law. The courts of Thessaloniki, Greece, have exclusive jurisdiction over disputes between the parties. This does not affect the rights of data subjects to bring proceedings or lodge complaints under the GDPR.