Stage 1 ISEB Pre-Test and Stage 2 Harrow Test — everything families need to know.
Book a Free ConsultationHarrow School is one of England's most prestigious boys' boarding schools — founded in 1572 under a Royal Charter from Elizabeth I, located in Harrow on the Hill, Middlesex, and admitting approximately 160 boys each year into Year 9 (joining at age 13). Entry to Harrow School is a two-stage process beginning in Year 6: Stage 1 is the ISEB Common Pre-Test, taken at the candidate's own school in the autumn term; Stage 2 is the Harrow Test, held at Harrow School itself in the spring term, consisting of a computerised English and Maths assessment, a group activity, and a one-to-one interview with a Housemaster. Families in Harrow borough also commonly target John Lyon School — a selective independent boys' day school within the same Foundation — along with Merchant Taylors' in Northwood and Haberdashers' Boys in Elstree, all of which use the ISEB Common Pre-Test as their first-stage filter. This guide covers both stages of the Harrow School admissions process in full, what Harrow is looking for at each stage, how to prepare effectively, and how Leading Tuition supports families through the process.
Harrow School occupies a 300-acre hilltop campus at Harrow on the Hill (HA1 3HP), approximately 12 miles from central London. It is a full-boarding school for boys aged 13 to 18, with over 800 pupils organised into eleven Houses. Founded in 1572 under a Royal Charter granted by Queen Elizabeth I, Harrow is among the world's best-known schools — notable for its academic tradition, its long list of distinguished alumni including Winston Churchill, Lord Byron, and Jawaharlal Nehru, and its insistence on boarding as a complete way of life, not merely an accommodation arrangement.
Academically, Harrow is highly selective and consistently strong. Leavers regularly secure places at Oxford, Cambridge, Imperial College, and other leading universities in the UK and internationally. The school looks for boys who will flourish intellectually, contribute meaningfully to school life beyond the classroom, and thrive in an all-boarding environment. These qualities — not just examination scores — define what makes a successful Harrow applicant. The admissions criteria explicitly list: a boy who will thrive in a boarding environment and make the most of the opportunities offered; who will make a positive contribution to school life inside and outside the classroom; who is talented academically or in sport, the arts, or other areas; and who has a good behavioural record and the potential to show leadership.
Around 160 boys are admitted into Year 9 each year. The registration deadline for standard applicants is 1 July of Year 5, with a non-refundable registration fee of £450. Families who register after the end of Year 5 are considered Late Applicants and compete for fewer places. Registering early is strongly recommended — ideally in Year 4 or early Year 5.
Harrow borough has no state grammar schools. Families seeking selective secondary education are looking at independent schools, and the most significant local option — beyond Harrow School itself — is John Lyon School in Harrow on the Hill. John Lyon is a selective independent day school for boys within the John Lyon's Foundation, admitting around 100 boys into Year 7 each year. It consistently produces strong academic results and draws applicants from across north-west London, including Harrow, Pinner, Northwood, Stanmore, and Wembley.
Many families in and around Harrow also apply to Merchant Taylors' School in Northwood and Haberdashers' Boys' School in Elstree — both highly selective independents that also use the ISEB Common Pre-Test as a first-stage filter. This means a single, well-prepared ISEB performance can support applications to multiple schools simultaneously, including Harrow School (for 13+ entry), John Lyon (for 11+ entry), Merchant Taylors', and Haberdashers'. Planning preparation around this overlap — and understanding that the ISEB can only be sat once per academic year — is one of the most effective strategies for families in this part of north-west London.
The ISEB Common Pre-Test is a computer-based, adaptive assessment that all Harrow School applicants are required to sit in the autumn term of Year 6 — for standard applicants, between 1 October and the end of November. Boys who have already sat the ISEB Common Pre-Test for another school can have their results transferred to Harrow; they do not sit it again. The test is approximately two and a half hours in total and consists of four components, which may be completed together or at separate sittings.
Because the test is adaptive, the difficulty of each question adjusts in real time based on your child's responses. Children cannot skip or revisit questions within each section. This adaptive format means there is no fixed past paper to practise from in the conventional sense — a child who performs well will face progressively harder questions, and the test is designed to find the ceiling of their ability, not simply confirm they have covered the curriculum. This makes broad, genuine underlying ability significantly more important than pattern-recognition drills based on a fixed set of question types.
| Section | Format | What It Tests | When Taken |
|---|---|---|---|
| Verbal Reasoning | Adaptive, computer-based | Vocabulary, analogies, word relationships, logical deductions | Autumn term, Year 6 |
| Non-Verbal Reasoning | Adaptive, computer-based | Pattern recognition, spatial reasoning, visual logic | Autumn term, Year 6 |
| English | Adaptive, computer-based | Reading comprehension, language accuracy | Autumn term, Year 6 |
| Mathematics | Adaptive, computer-based | Upper KS2 curriculum applied under time pressure | Autumn term, Year 6 |
For boys at UK prep schools, the school typically handles registration and administration of the ISEB test on-site. Boys at state schools or schools unfamiliar with the process need to arrange a suitable testing room with a computer and internet access, and an adult to supervise — the school itself or a local educational venue can act as the invigilation centre. Families should visit the ISEB website for current registration guidance and to understand exactly what to expect on test day.
Boys who reach the required standard in the ISEB Common Pre-Test and receive a strong confidential reference from their school are invited — by the end of December of Year 6 — to sit the Harrow Test. This second stage takes place at Harrow School itself, across multiple sessions between early January and mid-February of Year 6. When invited, candidates are also asked to submit a handwritten CV — a brief personal profile written by the boy in his own hand, not typed and not parent-drafted.
The Harrow Test is a structured assessment that evaluates the whole boy, not just academic performance. It consists of three components, each designed to assess different qualities that Harrow values in its new boys.
The computerised English and Maths assessment (60 minutes total) is taken on screen at the school. This component tests command of English — reading, comprehension, language accuracy — and mathematical reasoning and problem-solving. Unlike the ISEB Stage 1, which adapts continuously, this assessment provides a direct measure of academic attainment in the two core subjects under timed conditions. Boys who have kept their academic work sharp throughout Year 6 and who are confident working at pace on screen will be best placed here.
The group activity (20 minutes) is a classroom-based collaborative exercise in which a small group of candidates works together on a task or discussion. Assessors are watching for how each boy behaves in a group setting — whether he listens as attentively as he speaks, whether he builds on others' contributions, whether he is the kind of person who makes the group more effective rather than less. It is not a public speaking test or a competition for airtime; it is an assessment of social intelligence, collaborative instinct, and intellectual generosity.
The Housemaster interview (20 minutes) is a one-to-one conversation between the candidate and a member of Harrow's House Master team. It is conversational and genuine in tone — the House Master is interested in who this boy really is: what he reads, what he is curious about, what he has achieved, what matters to him. Children who have a rich and authentic set of interests, who can talk about them with real enthusiasm and specific detail, and who can sustain a thoughtful two-way conversation, will find this stage plays directly to their strengths.
| Component | Duration | Format | What Is Assessed |
|---|---|---|---|
| English and Maths Assessment | 60 minutes | Computerised, on-site at Harrow School | Academic ability in English and Mathematics |
| Group Activity | 20 minutes | Classroom-based, collaborative | Teamwork, communication, intellectual engagement |
| Housemaster Interview | 20 minutes | One-to-one, conversational | Character, interests, suitability for boarding |
| Handwritten CV | Submitted at invitation stage | Written in boy's own hand | Personal profile, interests, achievements |
After the Harrow Test, results are communicated in late April or early May of Year 6. The school issues one of four outcomes: an A1 List (place offered in a specific House), an A2 List (place offered with House to be allocated later), a B List (Waiting List), or a C List (no offer). All A1 and A2 offers are conditional on the boy sitting Common Entrance examinations in June of Year 8 and meeting the required standard.
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Our specialist tutors cover both stages of the Harrow admissions process: ISEB Common Pre-Test preparation and Stage 2 Harrow Test coaching — including the computerised English and Maths assessment, group activity preparation, and mock Housemaster interviews.
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Book a Free ConsultationHarrow is explicit about the qualities it seeks in new boys, and the Stage 2 Harrow Test is designed specifically to assess them. Academic ability alone — even exceptional academic ability — is not sufficient. The school's admissions criteria list four dimensions: the ability to thrive in a boarding environment; the capacity to make a positive contribution to school life beyond the classroom; talent in academics, sport, the arts, or other areas; and a good behavioural record combined with the potential to lead.
In the group activity, assessors are watching for intellectual curiosity — does the boy engage with the task with genuine interest? — and collaborative spirit — does he listen to others as well as contribute, build on what others say rather than redirecting every comment to himself, and help the group function better as a result of his presence? These qualities cannot be faked in a 20-minute exercise with children who have never met before. They come from genuine character and, to some extent, from a childhood rich in collaborative activities: team sports, group music-making, debating, shared projects.
In the Housemaster interview, authenticity is what impresses. A boy who has real passions — a book series he has followed with genuine enthusiasm, a sport he has practised with commitment, a historical period he has read about beyond the classroom, a scientific problem he finds fascinating — will have specific, vivid, personal things to say. Assessors at Harrow are experienced interviewers and immediately notice the difference between a boy who is articulating his own genuine interests and a boy who is delivering a polished but hollow script. Help your son prepare by encouraging him to reflect on what genuinely matters to him — not what sounds impressive.
Stage 1 — ISEB Common Pre-Test preparation. For most families targeting Harrow School, serious preparation for the ISEB should begin 12 to 18 months before the test — meaning a start in Year 5 for standard applicants. The four ISEB subjects each require a different preparation approach. For verbal reasoning, regular reading of varied, challenging texts builds the vocabulary, inference and analogy skills the test rewards — this is a slow, long-term build, not something that can be accelerated with a few weeks of drilling. For non-verbal reasoning, structured practice with pattern and spatial reasoning tasks is essential because these question types do not appear in the school curriculum; most children encounter them for the first time in preparation materials and need adequate time to build genuine facility with them. For mathematics, strong fluency with the upper Key Stage 2 curriculum — fractions, decimals, percentages, ratios, geometry and problem-solving — applied quickly and accurately under time pressure, is the foundation. Timed, screen-based practice that mirrors the computer-delivered adaptive format should begin once subject knowledge is solid, to build the specific stamina and composure the test demands.
Stage 2 — Harrow Test preparation. Once a boy receives his invitation to the Harrow Test, preparation should focus on the three Stage 2 components. For the computerised English and Maths assessment, keeping academic work sharp throughout Year 6 and building comfort with timed tasks on screen is the right approach — boys who have been well-prepared for Stage 1 will already be in good shape for the academic elements of Stage 2. For the group activity, boys who regularly participate in team sports, school debating or drama, music groups, collaborative projects, or other activities where listening and contributing are both valued will find this component comes more naturally. Even boys who are quieter by nature can develop the skills of building on others' ideas and contributing at the right moment — it is something that can be practised and coached. For the Housemaster interview, the most important preparation is long-term: the cultivation of genuine, specific interests that the boy can talk about with real knowledge and enthusiasm. Mock interview practice in the weeks before the test can help him organise his thoughts, practise speaking clearly and conversationally with an adult he does not know well, and learn to respond to follow-up questions without becoming flustered.
For the handwritten CV, encourage your son to think about what genuinely matters to him: what he has achieved, what he is proud of, what he does outside school, what he has read. A short, honest CV written in a 12-year-old's authentic voice is considerably more compelling to Harrow admissions staff than a long, polished document that reads as though it has been written by a parent. Help him identify the content; let him write it himself.
Harrow School admits around 160 boys per year into Year 9, spread across eleven boarding Houses. The applicant pool is significantly larger: families apply from across the UK — with a strong concentration from London, the Home Counties, and major cities — alongside a substantial international contingent from Hong Kong, China, Singapore, and many other countries. A large proportion of UK applicants come from well-resourced prep schools that dedicate structured curriculum time to ISEB preparation, conduct mock assessments, and coach boys for school-specific admissions processes as a matter of routine.
There is no published pass mark for the ISEB Common Pre-Test at Harrow. The school uses ISEB results to identify boys who have reached the required standard and invites a subset to the Harrow Test. Even reaching Stage 2 is competitive — not every boy who passes the ISEB is invited. Of those who sit the Harrow Test, only a proportion receive offers, and the distinction between an A1 List place (specific house offered) and an A2 List place (house to be allocated) is meaningful: A1 boys have a named House Master and a boarding community they can begin to prepare for before the end of Year 6. A B List (waiting list) outcome can convert to an offer if other boys decline, but this is not guaranteed and varies significantly year on year.
All offers — A1 and A2 alike — remain conditional on the boy sitting Common Entrance examinations in June of Year 8. While Harrow does not apply a strict CE pass mark and uses results primarily for set placement, a boy who performs very well in the Academic Scholarship examinations may be exempted from sitting CE. The registration fee of £450 is non-refundable, so families should be confident before registering that Harrow School is a genuine target.
Leading Tuition provides specialist 1-to-1 tutoring for both stages of the Harrow School admissions process and for John Lyon School entry at 11+. For Stage 1, our tutors build genuine ability across all four ISEB components — verbal and non-verbal reasoning, English, and Mathematics — through structured, personalised programmes that identify each child's specific gaps and work systematically to address them. We conduct timed, screen-based mock assessments that replicate the adaptive format of the ISEB, so that children arrive on test day with the composure and stamina that the assessment rewards.
For Stage 2, we provide targeted preparation for each component of the Harrow Test. For the computerised English and Maths assessment, we build and maintain the academic skills and on-screen confidence boys need under timed conditions. For the group activity, we run structured coaching sessions that help boys practise the collaborative and communicative skills Harrow is looking for — listening, building, contributing at the right moment. For the Housemaster interview, we run mock interviews that help boys organise and articulate their genuine interests clearly, hold a thoughtful conversation with an adult they do not know, and manage the natural nerves that come with a one-to-one assessment.
We also work with families on the handwritten CV — not by writing it for the boy, but by helping him identify what matters most and find the words to say it authentically. Our students have achieved a 95%+ offer rate across selective school entry, and we are rated 4.8/5 on Trustpilot. Book a free consultation to discuss a tailored preparation plan for your son's timeline and target schools.
Harrow does not have state grammar schools. Selective secondary education in this borough means independent schools. John Lyon School is the most prominent local selective independent for boys, drawing applicants from across north-west London. Families seeking grammar school places typically look further afield — towards Buckinghamshire, where grammar schools are found across the county, or towards selective state schools in neighbouring boroughs. Harrow School itself is an independent full-boarding school for boys, separate from the state grammar system entirely and targeted by families across the UK and internationally.
Harrow School uses a two-stage admissions process for Year 9 entry (boys joining at age 13). Stage 1 is the ISEB Common Pre-Test — a computer-based, adaptive assessment covering verbal reasoning, non-verbal reasoning, English and Maths, taken at the boy's own school in the autumn term of Year 6. Boys who reach the required standard in the ISEB, and receive a strong school reference, are then invited to Stage 2: the Harrow Test. This second stage takes place at Harrow School itself in the spring term of Year 6 and includes a 60-minute computerised English and Maths assessment, a 20-minute classroom-based group activity, and a 20-minute one-to-one interview with a Housemaster. Results are communicated in April or May of Year 6.
The Harrow Test is held at Harrow School in the spring term of Year 6 and has three components. First, candidates sit a 60-minute computerised assessment covering English and Maths. Second, they take part in a 20-minute classroom-based group activity, assessed for collaboration, communication and engagement. Third, each candidate has a 20-minute one-to-one interview with a Housemaster. When invited to the Harrow Test, boys are also asked to submit a handwritten CV. The process is designed to assess not just academic ability but a boy's character, interpersonal skills and suitability for a full-boarding environment. Offers are made in late April or early May of Year 6.
John Lyon School uses the ISEB Common Pre-Test as its first-stage assessment, typically administered in the autumn term of Year 6. Shortlisted candidates are then invited to sit school-specific papers and assessments at the school in the spring term. Exact dates vary each year, so it is important to register early and monitor the school's admissions pages directly for current deadlines and registration windows. As with Harrow School, preparation for the ISEB Common Pre-Test is the critical first step — and the same targeted preparation supports applications to both schools and others in the area.
The ISEB Common Pre-Test is a computer-based, adaptive assessment used by many independent schools — including Harrow School and John Lyon — as a first-stage filter. Unlike a fixed paper, it adjusts question difficulty in real time based on your child's responses, and candidates cannot skip or revisit questions within each section. It tests four subjects: verbal reasoning, non-verbal reasoning, mathematics and English. Because it is adaptive and screen-based, preparation needs to go beyond practising printed past papers. Children also need to build comfort working under time pressure on a computer and develop genuine underlying skills, not just familiarity with question formats.
Leading Tuition provides specialist 1-to-1 preparation for both stages of the Harrow School admissions process and for John Lyon School entry. For Stage 1, our tutors build the verbal and non-verbal reasoning, maths and English skills the ISEB Common Pre-Test rewards. For Stage 2, we help boys prepare for the Harrow Test's computerised English and Maths assessment, coach for the group activity, and run mock interview practice to build genuine confidence and fluency. We are rated 4.8/5 on Trustpilot, with a 95%+ offer rate across selective school applications. Book a free consultation to discuss a tailored preparation plan for your child's timeline and target schools.
Further reading: 11+ Tuition at Leading Tuition | Harrow School 13+ Guide | All Borough Guides | Tutoring in Harrow
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