26 September 2025 · 12–14 mins read
Introduction
The ISEB Common Pre-Test is one of the most important milestones for families applying to selective independent senior schools in the UK. Taken by thousands of children each year, it serves as an initial academic filter before interviews, assessment days, or Common Entrance exams.
This guide is the definitive parent handbook: what the Pre-Test is, how it works, scoring, registration, preparation strategies, and FAQs for the 2025–26 cycle.
What is the ISEB Common Pre-Test?
The Independent Schools Examinations Board (ISEB) Common Pre-Test is a standardised, online, multiple-choice, adaptive exam used by over 100 leading senior schools including:
- Eton
- Harrow
- Winchester
- Westminster
- St Paul’s
- Charterhouse
- Wellington
It is called “common” because one test, one set of results is shared with all schools a candidate applies to — eliminating the need for multiple first-round exams.
Key Features:
- ✅ Online & Adaptive – difficulty adjusts depending on answers.
- ✅ Multiple-Choice – rough work allowed on paper (esp. in Maths).
- ✅ Purpose – measures both attainment & potential.
- ✅ Timing – about 2 hrs 15 mins total, split into 4 sections.
- ✅ Once Per Year – only one attempt between 1 Sept–31 Aug.
Who Takes the ISEB Pre-Test and When?
- Typical Age: Year 6 pupils (age 10–11) for Year 7 entry, or Year 7 for deferred Year 9 entry.
- When: Sat during Autumn/Spring Term (October–June).
- Where:
- At the child’s current prep/junior school
- At a senior school applied to
- At an approved test centre (e.g., British Council for overseas)
🌍 International applicants are supported, making the test accessible worldwide.
Test Format and Subjects
The Pre-Test is split into four timed sections:
| Subject | Duration | Content Focus |
|---|---|---|
| English | ~40 mins | Comprehension (fiction, non-fiction, poetry), spelling, grammar, punctuation, cloze tasks |
| Mathematics | ~40 mins | KS2 Maths: number, fractions/decimals/percentages, algebra, geometry, data handling |
| Verbal Reasoning (VR) | ~25 mins | Vocabulary, word codes, synonyms, antonyms, logic puzzles |
| Non-Verbal Reasoning (NVR) | ~30 mins | Shapes, sequences, rotations, 2D/3D spatial awareness puzzles |
👉 Total Time: ~2 hrs 15 mins (can be taken in one sitting or split).
Registration and Timeline
- Who Registers? Parents/guardians via the ISEB Guardian Portal.
- Applicant ID: Unique ID to share with all chosen schools.
- Fees: ~£100–£150 depending on test centre.
- Testing Window: Sept–June (schools may set deadlines Oct–Dec).
⚠️ Important: Only the first attempt counts in a given year.
Scoring and Results Explained
Parents don’t receive results — scores go directly to schools.
Scoring System:
- Raw Score → % correct answers.
- Adaptive Adjustment → difficulty-based weighting.
- SAS (Standardised Age Score) → adjusts for child’s age in months.
- Stanine (1–9): 9 = top, 1 = lowest.
- Percentile Rank → comparison vs peers.
📊 Example: SAS 120 = top 10% nationally.
Conditional Offers & Admissions Use
Schools interpret results differently:
- Filter: Who gets interviews/assessment invites.
- Benchmark: Combined with references and interviews.
- Offers: High scorers may get conditional offers (subject to CE or internal exams).
👉 No universal pass mark — a strong score at one school may not be enough for another.
Preparation Strategies
While designed to measure potential, preparation reduces stress and boosts accuracy.
- Start Early: Build English & Maths foundations in Year
- - Reasoning Focus: VR/NVR rarely taught in schools — practise separately.
- Timed Practice: Mock exams improve speed + stamina.
- Familiarisation: Use ISEB’s walkthroughs, Bond Online Premium Plus, Atom Learning, Century.
Daily Habits for Success:
- Encourage reading across genres for vocabulary + comprehension.
- Play logic/puzzle games for reasoning.
- Practise mental maths daily.
- Balance with rest, exercise, wellbeing.
📌 Special Considerations (SEND/EAL)
- SEND: Adjustments (e.g., 25% extra time, enlarged text) available with evidence (educational psychologist report).
- EAL: Students may apply for extra time or bilingual dictionaries (school approval required).
📌 Request adjustments during registration.
Key Takeaways for Parents
- ✅ Register via Guardian Portal – don’t rely on schools.
- ✅ Share Applicant ID with every senior school.
- ✅ Prepare steadily; avoid last-minute cramming.
- ✅ Focus equally on VR/NVR as well as English/Maths.
- ❌ Don’t expect to retake in the same year.
- ❌ Don’t panic about pass marks — thresholds vary by school.
❓ FAQs
How long is the ISEB Pre-Test?
About 2 hrs 15 mins, across four sections.
Can it be retaken?
No — only once per academic year (unless a technical fault occurs).
Do parents get the results?
No — scores are sent directly to schools, not parents.
When do schools use it?
Usually Autumn Term of Year 6, but deadlines vary by school.
What’s a good score?
There’s no set pass mark. SAS 120+ is considered strong, but schools differ in expectations.
Which schools use the ISEB Pre-Test?
Over 100 independents including Eton, Harrow, Winchester, Westminster, St Paul’s, Charterhouse, Wellington, and many more.
How does GLECTA help?
We provide ISEB-focused tutoring, mocks, and feedback, ensuring pupils are confident with adaptive questioning and timed conditions.
🔗 Quick Links (Parents)
- 📘 Our Courses
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