The road to a 13+ boarding school place is longer than most families expect. For schools like Eton, Harrow, Winchester and Radley, the process begins not in Year 8 but in Year 5 or 6, when boys sit the ISEB Common Pre-Test — an adaptive online assessment that determines whether a school will offer a conditional place years before Common Entrance is even sat. By the time a child reaches Year 8 and sits Common Entrance, the hard work of securing a place has often already been done — or not. Understanding this timeline, and preparing accordingly, is what separates families who feel in control from those who feel caught out.
The typical 13+ boarding school process runs as follows. In Year 5 or early Year 6, families register their son with their chosen schools. Each school has its own registration deadline — Eton's, for example, falls when boys are around 10 or 11 — so missing it can close the door entirely, regardless of ability.
Once registered, boys are invited to sit the ISEB Common Pre-Test, usually in Year 6 (age 10–11), though some schools allow it in Year 7. The test is taken online, either at the prep school or at a registered test centre. Results are sent directly to the schools the candidate has registered with.
Schools then use Pre-Test scores to shortlist candidates for interviews and assessments, typically held in Year 7. Strong Pre-Test performance leads to a conditional offer, which is confirmed — or not — when the boy sits Common Entrance in Year 8, usually in June. The whole process spans roughly three years from first registration to final confirmation.
The ISEB Common Pre-Test is an adaptive, computer-based assessment covering four areas: Mathematics, English, Verbal Reasoning and Non-Verbal Reasoning. Because it is adaptive, the difficulty of each question adjusts based on the candidate's previous answers, which means two children sitting the same test may encounter quite different questions. There is no fixed pass mark — instead, scores are reported on a standardised scale of 60 to 140, with a median of 100.
For the most selective schools — Eton, Winchester, Harrow, Radley, Charterhouse — a score in the region of 115 to 120 or above is typically needed to be competitive. A score of 100 is average; a score of 110 is solid but may not be enough for the very top schools. This is not a test where simply being bright and unprepared will do. The adaptive format rewards children who are fluent and fast across all four areas, not just strong in one or two.
The Maths section draws on the Year 6 curriculum but tests it at pace and depth. English covers comprehension, grammar and vocabulary. Verbal Reasoning includes word relationships, analogies and coded sequences. Non-Verbal Reasoning tests spatial and pattern recognition — skills that many bright children have never been explicitly taught. The pre-test is not only a 13+ gateway, either: Epsom College uses the same four adaptive papers to decide Year 7 entry outright, sat in the autumn of Year 6 with registration closing on 31 October.
Once a conditional offer is in place, attention turns to Common Entrance at 13+, sat in Year 8. Common Entrance is set by ISEB and marked by the receiving school. The standard benchmarks are well established: 60% is a pass, 65% is a solid performance, and 70% or above is distinction level. Most schools set their own internal thresholds, and some — particularly Winchester, which uses its own entrance examination rather than standard CE — have entirely separate papers.
Common Entrance covers a wide range of subjects including Mathematics, English, Science, French, History, Geography, Religious Studies and Latin. The depth expected at 13+ is considerable — CE Maths, for instance, includes algebra, geometry, statistics and number work at a level that requires sustained preparation across Years 7 and 8. For families looking to get ahead, our Common Entrance past papers and 13+ preparation resources are a useful starting point for understanding what the exams actually involve.
Schools issue conditional CE offers based on Pre-Test scores and interview performance, but those offers typically specify a minimum CE percentage — often 65% or 70% depending on the school and subject. Failing to meet that threshold in Year 8 can mean a place is withdrawn, even after years of preparation.
Our 13+ specialists work with students preparing for the ISEB Common Pre-Test, building the verbal, quantitative, non-verbal, and spatial reasoning skills the test assesses across its four sections. We're rated 4.8/5 on Trustpilot. Book a free consultation to discuss a preparation plan timed around your child's Pre-Test sitting date.
In the Pre-Test, the most common area of underperformance is Verbal and Non-Verbal Reasoning. These are not subjects taught explicitly in most prep school curricula, which means children who have not practised them are at a genuine disadvantage — not because they lack ability, but because they lack familiarity with the question types. A child who has never seen a coded sequence or a matrix pattern will lose time and confidence on questions that a prepared child finds straightforward.
In Maths, the issue is usually speed and fluency under pressure. The adaptive format does not reward slow, careful working in the way a written exam might. Children who are strong mathematicians but slow processors often score lower than expected. Drilling mental arithmetic and practising timed questions makes a measurable difference.
In English, vocabulary range is frequently the limiting factor. The comprehension and verbal reasoning sections both reward children who read widely and have a broad, precise vocabulary. One concrete preparation step that pays dividends: encourage your child to read a broadsheet newspaper or quality non-fiction for 15 minutes a day from Year 5 onwards. The vocabulary exposure alone will improve both English and Verbal Reasoning scores.
At Common Entrance level, the most common source of lost marks is incomplete subject coverage. Families often focus preparation on Maths and English while underestimating the demands of Science, French or Latin. A child who scores 75% in Maths but 55% in French may still fall short of a school's overall threshold.
Leading Tuition provides specialist 1-to-1 tutoring for every stage of the 13+ process — from Pre-Test preparation in Year 5 and 6 through to Common Entrance support in Year 8. Our tutors are experienced with the specific demands of the ISEB Common Pre-Test, including the adaptive format and the reasoning components that most prep school curricula do not cover in depth.
We work with families preparing for Eton, Harrow, Winchester, Radley, Marlborough, Rugby, Charterhouse, Oundle and other leading boarding schools. Tuition is tailored to the individual child — we assess where they are, identify the gaps that matter most, and build a structured programme that fits around school commitments. For Pre-Test preparation, we typically recommend beginning no later than the start of Year 6, and earlier for children targeting the most competitive schools.
The ISEB Common Pre-Test presents a particular preparation challenge because it is adaptive: question difficulty adjusts in real time based on performance, meaning candidates must maintain accuracy under pressure throughout the test, not just in the first few questions. A candidate who loses confidence mid-test and begins guessing on harder questions will see the algorithm adjust downward — a pattern that is difficult to recover from within the same sitting. Leading Tuition's ISEB pre-test coaching focuses heavily on this adaptive structure, teaching candidates to manage uncertainty under timed conditions and to approach each question type with a consistent strategy. Alongside the reasoning components, our tutors cover the English and Mathematics sections in depth, working through the curriculum content most commonly tested and building the speed of recall that the test's tight time limits demand. Preparation typically runs over two terms in Year 5 and the first half of Year 6, building steadily toward the test window in autumn and winter of Year 6. For the wider 13+ journey beyond the Pre-Test, including Common Entrance and school-specific guidance, see our full 13+ preparation hub.
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Book a Free Consultation Message us on WhatsAppIdeally, structured preparation should begin at the start of Year 6 at the latest — and in Year 5 for children targeting schools like Eton or Winchester where competition is particularly intense. The Pre-Test is typically sat in Year 6, which leaves limited time if preparation begins too close to the test date. Verbal and Non-Verbal Reasoning in particular benefit from sustained practice over several months rather than last-minute cramming.
Scores run from 60 to 140 with a median of 100. For the most selective schools — Eton, Harrow, Winchester, Radley — a score of around 115 to 120 or above is typically needed to be competitive. A score of 110 is solid but may not be sufficient for the top tier. Schools do not publish exact cut-offs, but Pre-Test scores are a primary shortlisting tool, so performance matters significantly.
Most schools use the ISEB Common Entrance papers, but some have their own examinations. Winchester College, for example, sets its own entrance exam rather than using standard CE. Schools also set their own internal thresholds — a 65% pass at one school may be a 70% requirement at another. It is important to check the specific requirements of each school your child is applying to, rather than assuming a single standard applies everywhere.
ISEB rules generally permit a candidate to sit the Pre-Test only once. This makes thorough preparation before the test date essential — there is no opportunity to resit if the result is disappointing. Some schools may consider alternative assessments in exceptional circumstances, but this is at the school's discretion and cannot be relied upon. Getting it right first time is the only realistic strategy.
After the ISEB pre-test, results are shared with the schools the family has registered with. Schools use these results, along with school reports and in many cases an interview, to decide whether to make a conditional offer of a place. A conditional offer means the school intends to accept the pupil subject to satisfactory Common Entrance results in Year 8. The gap between pre-test (usually Year 6 or 7) and CE (Year 8) is two or more years — which is why maintaining and building subject knowledge through that period is as important as the pre-test performance itself.
Leading Tuition provides specialist 1-to-1 coaching for the ISEB Common Pre-Test covering all four sections — verbal reasoning, non-verbal reasoning, English, and Mathematics. Our tutors build familiarity with the adaptive format, practise each question type systematically, and develop the timed accuracy that the test rewards. We also support the full 13+ journey beyond the pre-test: from interview preparation to subject-by-subject Common Entrance coaching in Years 7 and 8. Rated 4.8/5 on Trustpilot. Book a free consultation to discuss your child's preparation timeline.
Results are reported as a Standardised Age Score (SAS), a percentile rank and a stanine. According to ISEB's own Common Pre-Tests Support Portal, the SAS is scaled to an average of 100 with a standard deviation of 15, so roughly two-thirds of candidates (67%) score between 85 and 115, around 16% score above 115, and fewer than 5% score above 130. Because the score is age-standardised, children tested at different points in the school year are compared fairly against peers of the same age. As a rough guide, a SAS of 130 sits around the 98th percentile, 115 around the 84th, 100 is exactly average, and 85 sits around the 16th — but schools vary in how they use these figures, with some applying a fixed threshold and others weighing the score alongside references and interview performance.
The 11+ is used for entry to grammar and some independent schools at age 11 (Year 7 entry), typically sat in Year 6 using GL Assessment, CEM, or a school's own bespoke papers. The ISEB Common Pre-Test is also usually sat in Year 6, but it feeds into 13+ entry two years later — so a child can sit both in the same term for entirely different schools. The two overlap in content, since both test Maths, Verbal Reasoning and Non-Verbal Reasoning, so preparation for one builds skills relevant to the other. The key difference is format: the ISEB Pre-Test runs on ISEB's own specially developed adaptive online test player, where question difficulty adjusts in real time based on performance, unlike the fixed-difficulty, timed paper format most 11+ exams use.
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