Practical guidance from the Leading Tuition team
Book a Free ConsultationIf your child is applying to a selective independent school at 13+, you may have come across two very different assessments: the ISEB Common Pre-Test and the 11+. These are not the same thing, and confusing them can lead to misplaced preparation. Some families will sit only one; others will face both in the same academic year. Understanding the difference — and what each actually demands — is the first step to preparing effectively.
The ISEB Common Pre-Test is an online assessment developed by the Independent Schools Examinations Board (ISEB). It is used by many leading independent senior schools as part of their 13+ entry process. Rather than each school running its own preliminary screening test, a group of schools agreed to accept a shared pre-test result — hence the word "common."
The test is sat online, usually at the child's current prep school, and results are shared directly with the senior schools your child has registered for. It is not a final admissions decision — it is a pre-selection filter. Schools use the result to decide whether to invite a candidate to sit their main scholarship or entrance examinations at 13+, or in some cases to make a conditional offer well in advance.
The ISEB is administered through GL Assessment's secure platform. It is adaptive, meaning the difficulty of questions adjusts in real time based on how a child is performing. This is a crucial detail that affects how preparation should work.
The list of participating schools includes some of the most academically prestigious independent schools in England. Among those that use or have used the ISEB Common Pre-Test are Eton College, Harrow School, Winchester College, Marlborough College, Tonbridge School, Sevenoaks School, and a significant number of London day independents including Westminster School and St Paul's Boys' School.
It is worth checking directly with each school, as participation can change year to year and individual schools may supplement the ISEB with their own assessments or interviews. Some schools use the ISEB result as a hard filter; others treat it as one data point alongside school reports and headteacher references. Always read each school's admissions guidance carefully for the year your child is applying.
For families targeting multiple 13+ schools, the ISEB pre-test is often the single most important early hurdle — a poor result can close doors before the main examination season even begins.
The 11+ is a set of assessments used for entry into selective state grammar schools and some independent schools at Year 7 (age 11). It is typically sat in Year 6, in September or October, and results determine entry the following September. Different regions and schools use different versions — GL Assessment, CEM, or bespoke papers — and the format varies considerably.
The ISEB Common Pre-Test, by contrast, is part of the 13+ entry process. It is also usually sat in Year 6 — often in the autumn term — but it is selecting children for entry at age 13, two years later. This means a child can sit the ISEB pre-test and a grammar school 11+ in the same term, for entirely different schools and entry points.
The content overlap is real: both assessments cover Maths, Verbal Reasoning, and Non-Verbal Reasoning. A child preparing thoroughly for a GL Assessment 11+ will be building skills directly relevant to the ISEB. However, the adaptive online format of the ISEB is fundamentally different from a timed paper-based test. Standard timed paper practice does not replicate the experience of questions that get harder — or easier — based on your previous answer. Familiarity with the online interface and the psychological experience of adaptive testing matters.
The ISEB Common Pre-Test covers four subject areas:
Each section is multiple choice and completed online. The adaptive nature means two children sitting the same test will not see the same questions. A child who answers correctly will be presented with progressively harder items; one who struggles will receive easier ones. The algorithm uses this to generate a scaled score that reflects ability level more precisely than a fixed-difficulty paper would.
The English section is often the one families underestimate. Vocabulary range and reading comprehension at a high level are tested, and children who read widely tend to perform significantly better here than those who have focused preparation only on Maths and reasoning.
One of the most common frustrations parents encounter is that ISEB does not release past papers. Unlike the 11+, where many schools publish years of past papers, the ISEB provides only official familiarisation materials — short sample questions designed to show children the format and interface before the real test. These are available through the ISEB website and are worth working through carefully, but they are not sufficient on their own as a preparation resource.
For broader practice, the most effective approach is to use high-quality 11+ preparation materials alongside the official ISEB samples. You can find ISEB familiarisation papers and other independent school 11+ past papers that cover the same subject areas and give children the volume of practice they need to build confidence and speed.
Because the test is adaptive, preparation should focus on genuine understanding rather than technique alone. A child who has learned to spot patterns in non-verbal reasoning without understanding the underlying logic may perform well on fixed-difficulty papers but struggle when the adaptive algorithm pushes into harder territory. Depth of understanding matters more here than it does in some other assessments.
Preparation timelines vary, but most families begin focused work six to twelve months before the test date. For a child sitting the ISEB in the autumn of Year 6, that means starting in Year 5 or early Year 6. Children who are also preparing for a grammar school 11+ can integrate both strands of preparation efficiently, since the content overlaps substantially.
Working with a tutor who understands both the ISEB format and the 13+ admissions landscape can make a significant difference — not just in subject knowledge, but in helping a child manage the particular pressure of an adaptive online test. Leading Tuition works with families preparing for both the ISEB and 11+ entry routes, and can help identify where a child's preparation is strongest and where it needs more work.
When is the ISEB Common Pre-Test typically sat?
Most children sit the ISEB Common Pre-Test in the autumn term of Year 6, usually between September and November. This is the same period as many grammar school 11+ tests, so families targeting both selective state and independent senior schools often have a very busy few months. The exact date is arranged through the child's current school, which acts as the test centre.
Can a child resit the ISEB Common Pre-Test?
In most cases, no. The ISEB Common Pre-Test is designed to be sat once, and the result is shared with all the senior schools a child has registered with. There is no standard resit process. This makes thorough preparation before the test date particularly important — there is no opportunity to improve a score after the fact.
How long should preparation for the ISEB take?
Most families benefit from six to twelve months of structured preparation. Children who are also preparing for a grammar school 11+ can align much of their work, since Maths, Verbal Reasoning, and Non-Verbal Reasoning feature in both. The English component of the ISEB rewards long-term reading habits as much as targeted practice, so starting early — and reading widely — pays dividends.
Does a high ISEB score guarantee a place at a school?
No. The ISEB Common Pre-Test is a pre-selection filter, not a final offer. A strong score means a school is likely to invite your child to the next stage — typically a scholarship or entrance examination at 13+, plus an interview. The final admissions decision is made at that later stage, based on the full picture including academic performance, school reports, and interview. A high ISEB score opens doors; it does not guarantee entry.
For families preparing for selective independent school entry, you may also find these pages useful: 11+ tuition with Leading Tuition covers how structured tuition support works across both 11+ and pre-test preparation. For school-specific guidance, our 11+ school preparation guides cover entry requirements, past papers, and preparation advice for a wide range of selective schools.
The ISEB Common Pre-Test is a high-stakes assessment that many families encounter with little warning. Understanding what it is, how it works, and how it fits alongside other selective school assessments gives your child the best possible foundation — and removes a great deal of unnecessary anxiety from the process.
Book a free consultation and we’ll help you find the right support for your child.
Book a Free Consultation