The ISEB Common Pre-Test: a parent’s guide
Last updated August 2026
The ISEB Common Pre-Test is an online, adaptive admissions test taken by children applying to many of the UK’s leading independent senior schools.
It covers English, mathematics, verbal reasoning and non-verbal reasoning, takes around two and a quarter hours, and is usually sat once in Year 6. Because it is a shared assessment, a child sits it a single time and the result goes to every senior school they have applied to.
For most families it is the first formal hurdle in the senior school process, and it arrives earlier than parents expect. This guide covers what the test contains, how the adaptive format works, which schools use it, how registration has changed and what sensible preparation looks like.
Who takes the test, and when
The Pre-Tests are designed for pupils in Years 6 and 7. Most children sit them in Year 6 for entry into Year 7 at 11+. Some senior schools, including Eton and Harrow, use the same test as the first stage of a much longer process leading to Year 9 entry at 13+.
The 2026-27 testing session runs from 1 September 2026 to late May 2027. Within that window, individual schools set their own deadlines, and those deadlines are usually much tighter than ISEB’s. Harrow, for example, asks all standard applicants to sit the test between 1 October and the end of November of Year 6. Eton asks for October or November. The practical rule is that the senior school’s deadline is the one that matters, so check every school on your list rather than assuming the full window is available.
A child can only sit the Pre-Tests once in an academic year. If somebody does sit them twice, the first set of results stands.
What is in the test
There are four tests, all online and all multiple choice. They can be taken together on one day or split across several, depending on what the invigilation centre arranges. Together they take two hours and fifteen minutes, with 25 per cent extra time available for eligible candidates.
The English test covers two areas. Reading comprehension uses short passages of roughly 300 to 500 words, which may be fiction, non-fiction or poetry, followed by multiple-choice questions on retrieving information, making inferences, explaining the meaning of words in context, explaining how word choice shapes meaning, summarising main ideas and making comparisons across a text. The grammar section covers vocabulary, punctuation, grammar and spelling. Notably, ISEB says most grammar questions ask what is grammatically correct rather than requiring children to recall the names of specific tenses, though they are expected to identify nouns, verbs, adjectives, adverbs and prepositions.
The mathematics test draws on the National Curriculum programme of study up to the end of Year 5: number and place value, the four operations, fractions, decimals and percentages, measurement, geometry and statistics. Some questions test straightforward arithmetic fluency, others are multi-step problems.
Verbal reasoning uses letter, word and language-based questions to measure comprehension, reasoning and logic, with a strong emphasis on vocabulary. Non-verbal reasoning splits into two types: pattern work on 2D figures and diagrams, and spatial reasoning that asks a child to manipulate 3D shapes mentally.
Neither reasoning paper is taught on the national curriculum, which is why they tend to be the two that unsettle children most. That is a familiarity problem rather than a knowledge one.
How the adaptive format works
This is the part worth understanding properly, because it changes what good preparation looks like.
The Pre-Tests are computer-adaptive. After each answer, the system assesses the child’s ability and chooses the next question at the most appropriate level of difficulty. Get a run of questions right and the questions get harder. Get them wrong and they get easier. Every child follows a unique path, and two children sitting on the same morning may see a different number of questions.
Two consequences follow. The first is that a child cannot go back and change an answer. Once a question is submitted, it is gone, which makes careful reading on the first pass more valuable than a review strategy. The second is that the test is meant to feel hard. A child who finds the questions getting steadily more difficult is doing well, not badly. Children often come out convinced they have failed because the end felt tough, and it is worth telling them beforehand that this is exactly how the test is designed to feel.
The online test player includes accessibility features as standard. Children can apply a coloured overlay, adjust font size and hide the countdown timer if watching it makes them anxious. The timer stays available to everyone, including those with extra time.
How the results are scored
Senior schools receive age-standardised scores. Raw marks are adjusted for a child’s age in years and months, then placed on a scale where the average is 100. The standardisation sample is drawn from the independent school sector, not the general school population, so a score of 100 means average among children applying to independent senior schools rather than average nationally.
Age standardisation is the reason ISEB says a younger child is not disadvantaged by their birth month, and a child is not disadvantaged by sitting the test in October rather than March. Both are accounted for in the scoring. Schools do not publish the scores they look for, and no school treats the Pre-Test as the whole picture: it sits alongside a head teacher’s reference and, at most schools, further assessment.
Which schools use the ISEB Common Pre-Test
ISEB does not publish a single public list of the senior schools that use the Pre-Tests, and the list changes. Rather than rely on a third-party roundup that may be out of date, check the admissions page of each school on your shortlist, which is where any change appears first.
Among schools that state their use of the test on their own admissions pages, Eton requires all boys to sit the Pre-Tests in October or November of Year 6 alongside a head teacher’s report, then invites successful candidates to a second-stage assessment at the school. Harrow requires all boys to sit the test between 1 October and the end of November of Year 6, uses the results and a school reference to decide who goes forward, and then invites those candidates to sit the Harrow Test in the spring term. Wellington College and Headington School are both users, with staff at each quoted on ISEB’s own site.
The pattern across schools is consistent even where the details differ. The Pre-Test is almost never the decision. It is the filter that decides who gets to the stage where the decision is made.
Registering: what has changed
Registration is now completed by the parent or guardian, not by the senior school. This is the single most common thing older guides get wrong, and it catches families out every year.
You register through ISEB’s Guardian Portal, where you create an Applicant Profile for your child and receive a unique Applicant ID. You then share that ID with each senior school and with the invigilation centre. Schools use the ID to find your child’s results in their own portal. You can also upload evidence of SEND or access arrangements through the Guardian Portal, and you can return to edit the profile before it is complete.
The test itself is sat at an invigilation centre. In most cases that is your child’s current junior or prep school, which ISEB recommends because it avoids a trip to an unfamiliar building. Where the current school cannot invigilate, an approved third-party centre can be used, including British Council offices, which is how most overseas candidates sit the test.
Key dates for 2026-27
9 June 2026 – the Guardian Portal opened for registration. ISEB asks that you do not attempt to register before the portal opens for a given session.
1 September 2026 – live testing begins.
Late May 2027 – testing for the session ends.
Senior schools set their own deadlines inside that window, and several close months before the ISEB date. Your child’s invigilation centre will confirm the actual testing dates.
How to prepare
The honest answer is that familiarity matters more than cramming. The English and maths content is drawn from the national curriculum a child has already covered, so there is rarely much to teach. What genuinely helps is a child knowing what the screen looks like, understanding that questions get harder as they do well, being comfortable that they cannot go back, and having seen enough verbal and non-verbal reasoning questions that the formats are not a surprise.
ISEB publishes a test walkthrough along with free guidance for families, and sells its own preparation materials. Working through official familiarisation material first is a sensible starting point before considering anything paid.
Beyond that, the risk runs the other way. Heavy drilling on a test designed to measure potential tends to produce anxious children rather than higher scores, and the second stage at most schools is an interview or an on-site assessment where a coached child is fairly easy to spot. Schools are looking for a child who is curious and can think, not one who has been rehearsed.
If your child needs support, the most useful kind is usually steady confidence-building over months rather than an intensive block in the weeks before. That is the approach we take with the families we mentor: work on how a child thinks and how they handle pressure, and let the test look after itself.
Common questions
Can my child sit the ISEB Pre-Test more than once?
No. A child can sit the tests only once in any academic year. If they somehow sit them twice, the first set of results stands.
Do I register with ISEB or with the school?
With ISEB, through the Guardian Portal. Parents and guardians now register directly and share the resulting Applicant ID with each senior school. Older guidance saying that schools register candidates is out of date.
How long does the test take?
Two hours and fifteen minutes across the four tests, which can be sat together or on separate days. Eligible candidates receive 25 per cent extra time.
Is my child disadvantaged by being young for their year, or by sitting the test early?
No. Scores are standardised for age in years and months, and standardised across the testing period, so neither a summer birthday nor an October test date should count against a child.
Are there past papers?
Not in the way there are for written exams. Because the test is adaptive and drawn from a question bank, no two children see the same paper. ISEB provides a walkthrough and official practice materials instead.
Does a good Pre-Test score mean an offer?
No. At most schools the Pre-Test decides who progresses to the next stage. Interviews, on-site assessments, head teacher references and, at some schools, a further Year 8 examination all follow.