Chislehurst and Sidcup Grammar School 11+ Guide 2026

Chislehurst and Sidcup Grammar School (CSGS) is one of four state grammar schools in the London Borough of Bexley, located on Hurst Road in Sidcup, SE9. A co-educational school educating pupils aged 11 to 18, CSGS offers 192 Year 7 places for September 2027 entry through the Bexley Selection Test — now provided by Quest Assessments following a change from GL Assessment in 2026. What makes CSGS distinctive within London’s grammar school landscape is its admissions structure: the school has no designated catchment area or geographical boundary. Any child who achieves the selective standard in the Bexley Selection Test, regardless of which borough or county they live in, is eligible to apply. When the school is oversubscribed — which it invariably is — distance from home to the school entrance on Hurst Road becomes the decisive criterion for the majority of places. This guide covers the test format, the full admissions process, oversubscription criteria, key dates for the 2026–27 cycle, and how to prepare effectively for a school where passing the test is just the beginning.

CSGS at a Glance

CSGS sits within the Bexley Grammar School Consortium alongside Beths Grammar School (boys), Bexley Grammar School (mixed) and Townley Grammar School (girls). All four schools use the same single test administered by the London Borough of Bexley, and a combined 800 Year 7 places are available across the consortium for September 2027. The selective standard is set collectively by the four grammar school headteachers in conjunction with Bexley Council, and in recent cycles approximately 35% of the roughly 5,000 children who sit the test have been deemed selective — meaning around 2,070 children qualify for grammar school consideration from a single cohort.

How Does the Bexley Selection Test Work?

For 2026 entry and subsequent cycles, the Bexley Selection Test is provided by Quest Assessments, replacing GL Assessment, which administered the test in previous years. It is important to note that the Bexley Quest test is a paper-based examination — fundamentally different from the online adaptive Quest assessment used by independent schools such as Dulwich College or City of London School for Girls. Families who have encountered Quest in an independent school context should not assume the format, difficulty, or preparation approach is the same. You can read more about the distinction in our Bexley Quest Assessment guide.

The test consists of two separate booklets, each lasting approximately 50 minutes, with all questions in multiple-choice format. The full session runs from two and a half to three hours, including initial instructions and a short break between the two papers. The three assessed areas are:

Verbal ability: This covers vocabulary, reading comprehension, and verbal reasoning skills. Children are expected to understand written passages, identify meanings, make inferences, and work with words and language patterns. Verbal ability is typically the section where preparation makes the most difference, as children who read widely from an early age have a natural advantage — but targeted practice with verbal reasoning question types can close gaps effectively for children who have not been reading extensively in English.

Numerical reasoning: Mathematics content does not exceed what children are expected to have learned by the end of Year 5, in line with the Key Stage 2 national curriculum. Questions cover arithmetic, number patterns, fractions, percentages, basic algebra, word problems, and data interpretation. Speed is critical: children need to work through multiple-choice questions efficiently under timed conditions, using the test booklet for working out (rough paper is not provided).

Non-verbal reasoning: This section tests the ability to recognise visual patterns, understand spatial relationships between objects, and make logical deductions without using words or numbers. Children rotate, reflect, and classify shapes, and complete series and analogies. NVR is often the area families underestimate, but practice with Quest-style NVR question formats is essential preparation.

Scores are age-standardised after marking, meaning younger children in the year group are not disadvantaged relative to older ones. The selective threshold is set each year by the headteachers and Bexley Council after all results are in — it is not fixed in advance. The official guidance and practice materials for the Bexley Selection Test are available on the London Borough of Bexley admissions pages.

Why Does CSGS Have No Catchment Area? What This Means in Practice

Unlike many London grammar schools — including several in Kent and Surrey which have designated areas or priority zones — Chislehurst and Sidcup Grammar School operates with no geographical boundary on eligibility. Any child anywhere in England can register for the Bexley Selection Test and, if deemed selective, can list CSGS as a preference on their Common Application Form. This is a deliberate feature of Bexley’s approach: the consortium schools admit on merit first (achieving the selective standard) and then by proximity.

In practical terms, this means that families in Bromley, Greenwich, Lewisham, Bexleyheath, Erith, and surrounding areas all compete on the same distance basis for remaining CSGS places once priority categories have been filled. It also means that families living very close to the school — within 1 to 2 miles — have a structural advantage in the oversubscription process, regardless of how high their child scored in the test, provided the child is deemed selective. A child with a very high test score but who lives 4 miles away may lose out to a child with a lower-but-still-qualifying score who lives 1.5 miles away. Understanding this mechanic is critical when deciding whether to invest heavily in test preparation, how to prioritise school preferences on the CAF, and whether to list CSGS as a first or second preference.

The no-catchment structure also has a practical implication for preparation strategy. Because children from multiple boroughs — including those from high-performing independent prep schools and highly tutored state-school applicants — all sit the same test, the competition for the selective standard itself can be intense. In the most recent cycle for which data is available, approximately 5,866 children sat the Bexley Selection Test and around 2,070 (35%) were deemed selective. Those 2,070 children then competed for 800 grammar school places across all four Bexley consortium schools — so achieving the selective standard is a necessary but not sufficient condition for receiving an offer at CSGS specifically. See our guide to standardised scores for an explanation of how age-standardisation works and what score ranges tend to indicate selective status.

What Are the Oversubscription Criteria at CSGS?

When more selective children apply for CSGS than there are places, the school applies its published oversubscription criteria in strict order. Understanding these criteria is essential for families who live some distance from the school or who want to maximise the chance of an offer.

Criterion 1 — Looked after children: Children who are in the care of a local authority, or who were previously looked after and were subsequently adopted or made subject to a child arrangements order, are given first priority provided they are deemed selective.

Criterion 2 — Pupil Premium: Up to 12 places are reserved for children eligible for Pupil Premium who are deemed selective at the time of application and who live within 5 miles of the school. These places are allocated in order of distance, with the nearest qualifying children receiving priority. This provision reflects the school’s commitment to widening access for disadvantaged pupils who live reasonably close but might otherwise lose out purely on distance.

Criterion 3 — Staff children: Children of parents or registered guardians who are employed by CSGS on a permanent basis and have been so for two or more years at the application deadline are given third priority, subject to being deemed selective.

Criterion 4 — Siblings: Children with a sibling attending CSGS in Years 7 to 12 at the date applications close are given priority under Criterion 4. This applies to full, half, adopted, step, and foster siblings living at the same address.

Criterion 5 — Distance: All remaining selective applicants who have not been allocated a place under Criteria 1 to 4 are ranked in order of straight-line distance between the applicant’s home address and the school entrance on Hurst Road. Distance is measured as a direct line (“as the crow flies”), not by road. In cases where a child lives between two parents at different addresses, the home address used is where the child spends the greater part of the school week.

Criterion 6 — Tie-break: Where two applicants’ distances are identical to 0.001 of a mile, the test score is used as a tie-breaker, with the higher scorer prioritised. If distances and scores are both identical, random allocation is used.

For families located at the margins — where distance to CSGS may or may not fall within the historical cut-off — it is worth considering whether to list other Bexley consortium schools (Beths, Bexley Grammar, Townley) alongside CSGS on the CAF to maximise the chance of receiving a grammar school offer at any of the four schools. Our specialist tutors are experienced in advising on preference strategy for the Bexley consortium. You can also see how CSGS fits into the broader Bromley 11+ landscape when planning your child’s application.

How Should Your Child Prepare for the Bexley Selection Test?

Effective preparation for the CSGS 11+ — and for the Bexley Selection Test more broadly — requires a different approach from preparation for independent school 11+ or other grammar consortia. Several factors make it distinctive.

Quest Assessments format, not GL Assessment: From 2026, the Bexley Selection Test is delivered by Quest Assessments. While the subject areas covered (verbal, numerical, NVR) are similar to GL Assessment, the specific question styles, vocabulary demands, and non-verbal reasoning formats differ. Practice materials designed for GL Assessment schools such as those in Kent, Buckinghamshire, or Trafford may not accurately reflect what CSGS candidates will face. Use Bexley-specific preparation resources and Quest-format practice papers wherever possible.

Paper-based, not digital: The Bexley Quest test is administered on paper at a supervised venue — not online. Children complete answers in the test booklet (not on an answer sheet), and all working must be done within the booklet because rough paper is not provided. This means children need to practise managing their working space within a booklet format and building the stamina to work through two 50-minute papers with only a short break between them.

Start preparation by January of Year 5 at the latest: For children targeting CSGS, we recommend beginning structured preparation by January of Year 5, giving at least 18 months before the September Year 6 test date. This allows time to cover all three areas methodically, identify weaknesses early, and build the timed exam technique that multiple-choice tests reward. Children who begin preparation in Year 6 are at a significant disadvantage relative to those who have been practising verbal and NVR skills from Year 4 or 5.

Focus on verbal reasoning and reading: The verbal ability component of the Bexley Selection Test is typically where the widest range of performance appears. Children who read widely — fiction, non-fiction, newspapers, and quality long-form writing — tend to outperform on vocabulary and comprehension questions. Structured verbal reasoning practice should run alongside broad reading, not replace it. Our specialist tutors work on comprehension strategy, inference skills, and vocabulary building alongside specific VR question-type practice.

NVR preparation matters: Non-verbal reasoning is often underestimated by families who assume it cannot be improved through practice. In fact, systematic practice with NVR question types — particularly the rotation, reflection, and series questions that appear in the Bexley test — can produce significant improvements, especially for children who are strong in verbal and mathematical reasoning but less experienced with visual-spatial tasks. Allow dedicated NVR preparation time rather than treating it as a last-minute addition.

Timed mock tests are essential: The full Bexley Selection Test session runs to nearly three hours. Children who have not practised under timed, exam-condition environments before the test day often find the stamina and pacing demands difficult to manage. We recommend sitting at least four to six full timed practice sessions in the months before the September test, ideally using past Bexley Selection Test familiarisation materials.

How Does CSGS Compare to the Other Bexley Grammar Schools?

CSGS is one of four grammar schools in the Bexley consortium, and all four share the same selection test. However, they differ in gender composition, location, and oversubscription patterns — which means the right school preference strategy depends on where your family lives.

Beths Grammar School is boys-only, located in Bexley village. It offers 180 Year 7 places and tends to have a tight distance cut-off for boys living in the southern and eastern parts of the borough. Bexley Grammar School is mixed, located in Welling, and offers 210 Year 7 places. Townley Grammar School is girls-only, located in Bexleyheath, and offers 218 Year 7 places. CSGS is mixed, in Sidcup, with 192 places.

Because all four schools use the same single test, a child need only sit the Bexley Selection Test once to be considered for any or all of the four grammar schools. The CAF allows parents to list schools in preference order, and the distance-based oversubscription criteria mean that geographical position relative to each school is a major factor in determining which school, if any, makes an offer. Families who live between Sidcup and Welling, for example, may be equidistant between CSGS and Bexley Grammar School and should consider both carefully when ordering preferences. Our specialist tutors can advise on preference strategy as part of our holistic 11+ preparation support for the Bexley consortium.

Frequently Asked Questions