Sir William Borlase’s Grammar School in Marlow is one of Buckinghamshire’s most sought-after co-educational grammar schools. It was founded in 1624 and marked its 400th anniversary in 2024. Its results are consistently outstanding, and each year it draws far more strong applicants than it has places to offer.
This guide explains what your child faces: the Buckinghamshire Secondary Transfer Test, the qualifying score and the targets you should realistically aim for, the key dates for September 2027 entry, how catchment and oversubscription work, and a preparation strategy built around how Borlase actually selects.
School overview
Sir William Borlase’s Grammar School (URN 136781) is a co-educational selective school for ages 11 to 18, based on West Street, Marlow SL7 2BR. In its most recent graded Ofsted inspection on 1 May 2024, the school was rated Outstanding in every category, including the sixth form.
The academic results are exceptional. At GCSE in 2024/25, the school recorded an Attainment 8 score of 72.4, with 96.7% of pupils achieving grade 5 or above in both English and maths and an EBacc average point score of 6.87, according to Department for Education data. (A Progress 8 score was not calculated for 2024/25 because there was no valid Key Stage 2 baseline for that cohort following the pandemic.) At A-level in 2025, 17% of grades were A*, 53% A*–A, 82% A*–B and 95% A*–C.
Borlase also has a distinct character. It is a Performing Arts College with a strong rowing tradition, and Olympic gold medallist Tom Dean MBE is among its alumni. Pupils who do well here tend to be academically able and curious, but also keen to throw themselves into sport, music and drama.
The entrance exam: the Buckinghamshire Secondary Transfer Test
Entry to Borlase is decided by the Buckinghamshire Secondary Transfer Test (STT), the common selection test used by all Buckinghamshire grammar schools and overseen by Buckinghamshire Council. The test is produced by GL Assessment.
The STT consists of two papers, each lasting roughly 60 minutes including instructions and practice questions. Between them, the papers assess verbal reasoning, non-verbal reasoning and mathematics. Questions are multiple-choice, and pupils mark their answers on separate answer sheets, so accurate transfer of answers under time pressure is a skill in its own right.
Children at Buckinghamshire state primary schools are normally entered automatically. If your child attends a school outside Buckinghamshire, or is privately educated, you must register them directly with Buckinghamshire Council during the registration window.
Pass mark and realistic score targets
The qualifying score for Buckinghamshire grammar schools is 121. This is a standardised score that combines both papers and adjusts for your child’s age, so younger children in the year group are not disadvantaged. A child scoring 121 or above is deemed to have qualified for grammar school entry.
A score of 121 only makes your child eligible. It does not secure a place at Borlase specifically. Borlase has a single Year 7 entry of 150 places (see below), and in most years more children score 121 or above than there are places available. When that happens, the school applies its oversubscription criteria rather than test rank, so a higher score does not buy a higher place in the queue.
Because the cohort is so strong, treating 121 as the goal is a mistake. We advise families to aim comfortably clear of the threshold in practice. That means consistently scoring around 80% or higher on realistic timed papers, the equivalent of roughly the mid-120s in standardised terms, so that an off day still leaves your child safely qualified. The real battle for a Borlase place is then about catchment, not about scraping the pass mark.
Key dates for September 2027 entry
For children seeking a place in September 2027, the timeline is:
- Registration opens: 10am, Friday 1 May 2026
- Registration deadline: 3pm, Tuesday 2 June 2026
- Test dates: 8 and 10 September 2026
You can confirm these dates and the registration process on the Buckinghamshire Council grammar schools and transfer testing pages. Missing the registration deadline means your child cannot sit the test, so diarise it early, especially if you are applying from outside the county.
It is also worth visiting the school. For 2027 entry, Borlase is running Open Mornings on 14 and 21 April 2026 and an Open Evening on 23 September 2026.
Competition and catchment
Borlase admits 150 pupils into Year 7 (Published Admission Number of 150 for September 2026 entry). Admission is overseen by Buckinghamshire Council, and the school has a defined catchment area with a priority area within it.
Once a child has qualified with a score of 121 or above, places are allocated according to the school’s published oversubscription criteria. Higher priority goes to looked-after and previously looked-after children, to children eligible on certain social or medical grounds, and to siblings. The priority area and then distance from the school are used to separate the remaining applicants. For most families, it comes down to where you live relative to the school.
Marlow is a compact town and demand is high, so families on the edge of the catchment can find that a qualifying score alone is not enough. Buckinghamshire Council publishes annual allocation profiles showing how places were filled. We recommend checking the most recent figures for Borlase before committing to it as a first preference, and listing other Buckinghamshire grammar schools as back-up preferences if your distance looks borderline.
Preparation timeline and strategy
The strongest candidates start early. Ideally, foundational work begins in Year 4: building vocabulary through wide reading, keeping arithmetic sharp, and getting comfortable with reasoning-style puzzles, long before any formal exam practice. This avoids the cramming and stress that comes from leaving everything to Year 6.
At Think Smart Academy we prepare children specifically for the Buckinghamshire STT. We teach all four areas, verbal reasoning, non-verbal reasoning, English and maths, separately, so each skill is built properly rather than blurred together. Lessons run in small groups, with classes capped at eight pupils, so every child gets real attention while still working alongside similarly motivated peers.
Through Year 5 and into Year 6, regular mock tests under timed, exam-style conditions are essential. They build the stamina and answer-transfer accuracy the real papers demand, and they give you an honest, evolving picture of where your child sits relative to the score they will need for a competitive school like Borlase.
Our High Wycombe centre is around 10 to 15 minutes from Marlow via the A404, and we also offer online tuition for families who prefer to prepare from home, so geography need not limit access to specialist preparation. If you would like an objective starting point, we offer a free diagnostic assessment that shows where your child stands across all four areas.
Common mistakes to avoid
- Starting too late. The STT tests reasoning skills that primary schools rarely cover in depth. Beginning in Year 6 leaves too little time to build them calmly.
- Treating 121 as the target. It is only the qualifying threshold. For a place at Borlase you need to be safely clear of it and well positioned on catchment.
- Ignoring catchment. A brilliant score does not help if you live beyond the distance at which places run out. Check the allocation data before setting your heart on Borlase.
- Neglecting non-verbal reasoning. It is often the least familiar paper and the easiest to improve with structured practice, yet the most commonly under-prepared.
- Skipping timed mocks. Children who only ever practise untimed are routinely caught out by the pace and the pressure of transferring answers on the day.
- Missing the registration deadline. No registration means no test, with no exceptions, which matters most for out-of-county families.
Next step
Borlase is an outstanding school, and a place there is worth working for, but the competition is real and preparation needs to be focused and honest from the start. The families who succeed are the ones who begin early, target a score comfortably above the threshold, and understand how catchment affects their chances.
If you would like to know where your child stands today, book a free assessment with us, or read more about our tailored preparation for Sir William Borlase’s Grammar School. It is the clearest first step towards a well-planned application.