If your child is applying to an independent senior school in London, there is a good chance the first formal hurdle will not be a paper sat in a school hall but a set of multiple-choice questions answered on a computer screen. The ISEB Common Pre-Test has become the default early-stage assessment for a large share of academically selective senior schools, used to create a consistent, comparable picture of each applicant before interviews, reasoning papers or further written exams. It is set by the Independent Schools Examinations Board (ISEB), the same body behind Common Entrance, and it is designed so that a child sits one assessment that several schools can read — rather than a different test for each.
This guide explains what the Pre-Test is, what it contains, when it happens and how the scoring works, drawing on ISEB's own published information. It is current for the 2026 admissions cycle. Individual schools set their own deadlines and use the results differently, so always confirm the specifics with each school you are applying to.
What the ISEB Common Pre-Test actually is
ISEB describes the Common Pre-Tests as "multiple-choice, adaptive, online tests" used by leading independent schools as part of the admissions process. Three features matter here. They are taken on a computer rather than on paper. They are multiple-choice, so a child selects an answer rather than writing one out. And they are adaptive: the questions a child sees adjust to how they are performing. Answer a run of questions correctly and the test serves up harder ones; struggle, and it eases back. The aim, in ISEB's words, is that children "don't spend time answering questions that are too hard or too easy," which lets the test reach an accurate measure of a child's level more quickly.
Because it is adaptive, two children sitting the same test will not see the same questions, and there is no fixed "pass mark" printed on the screen. What the school receives is a standardised score, explained further below.
The four sections
The Pre-Test is made up of four separate assessments. ISEB groups them into two that measure attainment — what a child has learned — and two that measure potential, or aptitude for learning.
| Section | What it covers | Standard time |
|---|---|---|
| English | Reading comprehension and grammar, including spelling | 40 minutes |
| Mathematics | The National Curriculum for mathematics up to the end of Year 5 | 40 minutes |
| Non-Verbal Reasoning | Non-verbal and spatial reasoning | 30 minutes |
| Verbal Reasoning | Word meaning, comprehension, reasoning and logic | 25 minutes |
English and Mathematics are the attainment papers, drawn from curriculum content a child should have covered by the end of Year 5. Verbal and Non-Verbal Reasoning are the aptitude papers, using question types a child may not have seen before to gauge how they analyse patterns and solve unfamiliar problems.
The four sections add up to a standard assessment length of two hours and fifteen minutes. Schools do not have to deliver all four in a single sitting, and there is usually a short break between sections, so the experience on the day may be spread out rather than continuous. Where a senior school agrees it is appropriate, applicants with additional needs can be granted 25% extra time on each section.
When children sit it
For most families, the Pre-Test is an 11+ event. Children typically take it during Year 6, for entry into Year 7, most commonly in the autumn term — the bulk of tests are completed in October and November — although some schools test into the spring term. ISEB's testing window for the 2026–27 cycle runs from September 2026 to late May 2027, with registration opening on 9 June 2026.
A smaller group of schools, including well-known boarding schools such as Eton and Harrow, use the Pre-Test as an early screen for 13+ entry into Year 9. In that case the assessment is still usually sat in Year 6, well ahead of the eventual point of entry, though arrangements vary by school and some 13+ timelines run later. Because the exact year group and deadline are set by each senior school rather than by ISEB centrally, the safest approach is to check directly with every school on your list.
A child may sit the ISEB Pre-Tests only once in any academic year. There is no resitting to improve a score within the same cycle.
One test, shared with several schools
The defining feature of the Pre-Test is that it is a shared assessment. A child takes it once, and the result is made available to all of the senior schools that require it. As ISEB puts it, results "can be shared with multiple schools, which means the pupil only needs to sit the tests once," and schools can access them through their admissions portal soon after the test is taken. For families applying to several schools, this is a meaningful simplification: there is one assessment to prepare for and sit, not one per school.
How the scoring works
Schools do not receive a raw mark. Instead, each child's performance is converted into a Standardised Age Score (SAS). This adjusts for a child's age in months, so that a summer-born child is not unfairly compared against an older autumn-born one, and places the result on a scale where 100 is the average for the cohort. The standardisation is drawn from a sample of pupils applying for independent school places across the year, meaning a child is measured against the relevant applicant population rather than the national average. Age-standardisation is the reason the Pre-Test can be sat on different dates and still produce fair comparisons.
Schools then interpret these scores in their own way and alongside other evidence; ISEB provides the score, not an admissions decision.
Where the test is taken
The Pre-Test is sat under supervision, and ISEB recommends that, wherever possible, children take it in their own junior or prep school "to reduce anxiety" in a familiar environment. Where that is not possible, a child can sit the test at the senior school they are applying to, or at an approved independent invigilation centre — including, for families based abroad, centres outside the UK. The test runs in a browser on a computer, so the setting is a quiet, invigilated room with a suitable device rather than a formal examination hall.
Which schools use it
The Pre-Test is widely adopted across the selective independent sector. Schools that use it as part of their admissions process include Eton, Harrow, Westminster, St Paul's, Wellington College, Charterhouse, Brighton College, City of London School and University College School, among many others. The list changes from year to year, and a school using the Pre-Test will usually pair it with its own later stages — interviews, group activities or further reasoning and subject papers — rather than relying on it alone. The Pre-Test is the front door, not the whole house: it helps a school decide whom to look at more closely, and the offer comes later.
The practical takeaway for parents is straightforward. The ISEB Common Pre-Test is a single, computer-based, adaptive assessment of English, maths and reasoning, sat once in Year 6 (occasionally Year 7 for some 13+ routes), scored in an age-fair way, and shared with the schools you have applied to. Knowing that shape — and confirming each school's own deadline — is most of what a family needs before deciding how, and how much, to prepare.
