Chislehurst and Sidcup Grammar Sixth Form Entry 2026

Chislehurst and Sidcup Grammar School is a co-educational academy grammar school in Sidcup, in the London Borough of Bexley, whose sixth form admits a minimum of 80 external students into Year 12. Entry requires seven full-course GCSEs at grades 9–5 including English and Mathematics at grade 5 or above, plus an average point score of at least 6.5. A Level Mathematics additionally requires grade 8 and a pass in the school's own aptitude test.

Those three conditions are the whole of 16+ entry, and none of them appear together on any single page of the school's website. They are spread across an admissions policy, an entry-requirements sheet, a subject booklet, two key-dates documents and an enrolment page — and the versions disagree with one another. The section below sets out where each figure comes from and which document an appeal panel would actually read.

Which of the Five CSGS Documents Governs 16+ Entry?

Search for this school's sixth form entry requirements and the fifth organic result is a copy of the admissions policy hosted on a revision website, filed under the name Admission Policy 2026-27 with proposed changes. Nothing on the file says it is superseded. It is the consultation draft that circulated in May 2025, and on the single most consequential figure it is wrong by a full grade.

The draft says A Level entry requires "a minimum of a grade 7 at GCSE (8 for Further Maths)". The determined policy published on the school's own site says "a minimum of a grade 8 at GCSE (9 for Further Maths)". A student who plans around the draft, sits their GCSEs and comes out with a 7 in Mathematics will find they are a grade short of the subject they applied for. The draft also carries a paragraph offering a CSGS scholarship to "gifted musicians, athletes, actors and artists" that was cut from the determined version, although the school prospectus still describes scholarship programmes in Art, Arts and Performance, Music and PE for candidates with a minimum of grade 5 in English Language and Mathematics.

Those two differences are the only substantive edits between the draft and the determined policy at 16+. Everything else is identical. That makes the draft particularly easy to mistake for the current document, because it looks right in every respect a reader is likely to check.

Which governs. The determined Admissions Policy 2026–2027 is the statutory document. It is what the school consulted on, what the governing body determined, and what an independent appeal panel would apply if a place were refused. But it is also the thinnest of the five: it never mentions the Mathematics Aptitude Test, it gives one blanket sentence for all three sciences, and it says nothing about Computer Science, Economics, Business, Music, Physical Education or Psychology. The Entry Requirements sheet and the Subject Information booklet are what the school actually runs the process on, and both are stricter. The practical answer for any applicant is to meet the strictest published version of every condition, and to treat the determined policy as the floor rather than the specification.

The confusion does not stop at the school's own documents. The fourth organic result for this exact query is a PDF from Carshalton High School for Girls in Sutton, which ranks on the coincidence of its domain acronym. Its rule — "5 subjects, grades 9 – 4" — is far softer than Chislehurst and Sidcup's, and it lists BTEC Level 3 courses that Chislehurst and Sidcup does not offer at all. It is a different school fifteen miles away.

How the Average Point Score of 6.5 Works, and Where It Bites

The school's general requirement is "7 full course GCSEs at grades 9 - 5 which must include English, Mathematics (English & Maths grade 5 or above) and an average point score (APS) of at least 6.5". Most readers stop at the grade range and assume that seven passes at grade 5 will do. They will not. The APS is a separate gate applied on top, and it is the one that quietly removes the largest number of applicants.

Chislehurst and Sidcup does not publish how the average is calculated or across how many subjects. On the natural reading — that it is taken across the seven qualifying GCSEs — the arithmetic is worth doing before results day, because the answer is not intuitive.

An APS of 6.5 across seven subjects needs 6.5 multiplied by 7, which is 45.5 points. Since GCSE grades are whole numbers, the first total that clears the bar is 46. That produces a sharp boundary:

The row that matters is the third one. A candidate with three grade 7s and four grade 6s has met the grade range in full, has English and Mathematics comfortably above the grade 5 floor, and still fails the general requirement on an average that falls two-hundredths of a point short. Under the school's own oversubscription rules that same average is then used again, this time as the ranking mechanism for external places. The APS is not a formality at the door; it is the number that decides the queue.

Because the school does not name the subject set, a candidate whose eighth and ninth GCSEs are stronger than their seventh should ask the sixth form admissions team directly which subjects are counted before assuming the best seven apply. That question takes one email and can change the answer by a whole grade.

This is a materially different mechanism from the one used at the other selective sixth form in the same borough. Bexley Grammar School ranks applicants on a points total drawn from the best eight GCSEs rather than an average across seven, and Beths Grammar School operates on grade thresholds without an averaging step at all. Three neighbouring Bexley grammar schools, three incompatible formulae. Nothing about one transfers to another.

Who Gets Invited to the CSGS Mathematics Aptitude Test?

Sixth form entry here is not decided on GCSE grades alone. To take Mathematics or Further Mathematics at A or AS Level, a candidate must pass the CSGS Mathematics Aptitude Test, referred to throughout the school's subject booklet as the MAT. The test is not open to everyone who applies: "External applicants need to be predicted grade 8 or above for GCSE Maths to be invited to sit the CSGS aptitude test." A predicted grade 7 does not produce an invitation, and without an invitation there is no route to A Level Mathematics.

For September 2026 entry the test ran on 9 and 10 March 2026 for external applicants, and in the week commencing 9 March 2026 for the school's own Year 11 students. Drama and Music auditions followed on 13 March 2026. Candidates who are invited book their own slot through the online application.

The conditions are unusually bare. The school states plainly that "There will be no formulae provided" and "You will not need a calculator", and asks candidates to bring a pencil or pen, a ruler and an eraser. The published revision list covers algebraic fractions, algebraic proof, changing the subject of a formula, completing the square, direct and inverse proportion, equations of circles, expanding and factorising, functions, laws of indices including fractional and negative indices, quadratic graphs, simultaneous equations, solving equations and inequalities, straight line graphs, surds, transformation of graphs, trigonometric values and graphs, and trigonometry of both right-angled and non-right-angled triangles.

Two details in that list change how a candidate should prepare. Non-calculator trigonometry of non-right-angled triangles means the sine and cosine rules from memory, with exact values rather than decimals. Equations of circles and transformation of graphs sit at the top of the Higher tier and are frequently the last topics a Year 11 class reaches, so a March test can arrive before they have been taught in depth.

Three further conditions are set out only in the subject booklet. The MAT "is for invitees only and can only be sat once" — there is no resit, and a candidate who is unwell on the day has no second attempt within the cycle. Further Mathematics requires grade 9 at GCSE and "a higher-level pass" on the same paper, so one sitting is marked against two standards. And where A Level Mathematics is heavily oversubscribed, "priority will be given to applicants with an APS of 7 and above", which brings the average point score back into play a second time.

There is one documented way in without the test, and the school states it on its enrolment page: a candidate who has "not sat or not passed our Maths Aptitude Test (MAT)" will "require grade 9 in GCSE Mathematics to be considered", with "priority given to applicants that passed the MAT". The subject booklet frames the same allowance more tightly, as something granted "in exceptional circumstances". Either way it is a worse position than a MAT pass, not an equivalent one. Sitting the test is the stronger route, and preparing for it is closer to A Level Mathematics groundwork than to GCSE revision.

Auditions, Portfolios and the Subject Rules the Admissions Policy Leaves Out

Mathematics is not the only subject with a non-grade hurdle. Drama and Music are auditioned, and both Art and Design and Technology carry a portfolio clause.

For Drama, candidates prepare a monologue: "The monologue should be no more than two minutes in length and come from a professionally published play of your choice", performed to the Curriculum Leader as part of the admissions process. For Music, the performance "should last between 2 and 5 minutes" on a first instrument or voice, an accompanist can be provided if sheet music is supplied at least two weeks beforehand, and the ability to read notation in both treble and bass clef must be demonstrated at the audition itself. Auditions are by invitation, issued by email. For Art the school "reserve the right to request an electronic portfolio showcasing artistic ability", and Design and Technology carries the same reservation for a design-based portfolio.

The subject floors themselves are where the documents diverge most sharply. The determined admissions policy handles all three sciences in a single sentence: "Science requires grade 7 in separate Sciences (Biology, Chemistry and Physics) or two Grade 8s or above in Combined Science Trilogy." The entry-requirements sheet does not agree. Physics there carries an additional condition the policy omits entirely — "and grade 7 or above in GCSE Mathematics" — and the subject booklet adds that Physics candidates are strongly recommended to take A Level Mathematics alongside it. A student reading only the statutory policy would not know that Physics has a Mathematics gate.

Two rules apply across the whole list. Where a subject is oversubscribed, "preference will be given to those students who have achieved a grade 7 or higher" — and for Biology, Chemistry and Computer Science the booklet raises that preference to grade 8. And Business and Economics are mutually exclusive: "Students may opt to take either Business or Economics, but may not select both subjects." That restriction is stated only in the subject booklet, and it removes a combination that applicants to commerce-facing degrees commonly propose.

Why Your Postcode Barely Counts at 16, and How Many External Places Exist

The determined policy states that "The Published Admission Number (PAN) for Year 12 is a minimum of 80 external places." The wording is worth reading twice. Most schools publish a PAN as a ceiling. Chislehurst and Sidcup publishes it as a floor, which is the school's own way of saying it will not admit fewer than 80 external students and may admit more if the applicants meet the criteria. The prospectus describes the practical outcome as "over 70 students from other schools each year", joining a sixth form the school describes as a community "of over 500 students". So the external cohort has recently been running at or a little below the published minimum rather than pressing against a cap.

What decides who gets those places is a much shorter list than the one used at 11. The 16+ oversubscription criteria run to three items: looked-after and previously looked-after children first, then "Rank order of their average APS points score", then, only where two candidates have identical scores, "proximity to the school will be used as a tie break", measured in a straight line to the Hurst Road entrance.

Set that against the seven ranked criteria the same policy applies at age 11, where up to 12 Pupil Premium places come before the top-scorer band, siblings in Years 7 to 12 rank fourth, children of staff of two or more years' standing rank fifth, and distance is criterion six — the criterion that in practice fills most of the 192 places at Year 7.

The consequence is worth stating flatly, because families who were unsuccessful at 11 often assume the geography that counted against them will count again. It will not. There is no catchment area at 16, no priority zone, and no advantage for a sibling already at the school or for a child of a member of staff. A candidate living well outside the ring of postcodes that dominates Year 7 admissions competes on the same basis as one living on Hurst Road, and is separated from them only by average point score. Distance re-enters the process only when two applicants finish on an identical average. For families across Bromley and the surrounding boroughs, 16+ is the entry point where the geography of Bexley grammar admissions stops mattering.

Two further eligibility details are published only in the policy. Applications are considered "from students on a case by case basis who are no more than one year older (that is, they were born no later than 31st August 2008) provided that they are in Year 11 at a secondary school". And a name can join the Year 12 waiting list only if the applicant is "predicted to meet the entry requirements" — the waiting list is not open to candidates whose predictions fall short.

When the 2026 Deadlines Fell, and the Fortnight External Applicants Lose

The school publishes two separate key-dates documents, one for its own Year 11 students and one for external applicants. Placed side by side they show a gap that neither document mentions: external candidates get two weeks less to decide.

The reference requirement is the step external families most often underestimate. An academic reference has to be requested from the candidate's current school, written, and returned to Chislehurst and Sidcup by 20 February 2026 — four weeks after the application itself closes, and during a period that includes a half-term break. The request needs to be made at the point of applying, not after.

One caution about the school's own documents. The external key-dates sheet contains two clear typographical errors: it dates the first day of Year 12 term as "3rd Sept 2025" and the Year 12 welcome evening as "Sept 2025", both in a document about September 2026 entry. The internal version of the same sheet gives the correct "3rd Sept 2026". Where the two disagree on a year, the internal document is the one that reads consistently.

Anyone who reached this page while researching entry a year earlier should note that the September 2026 cycle described here is the most recently published one and has already closed — the school's application page states that applications are now closed. The 2027 documents had not been published at the time of writing. The structure, however, is stable year to year, and the 2026 dates are the best available guide to when the 2027 equivalents will fall.

Enrolment on 20 August 2026: Online Only, 10am to 5pm

A conditional offer at Chislehurst and Sidcup is confirmed on GCSE results day itself, not before. The school's key-dates documents record 20 August 2026 as "GCSE Results Day AND Sixth Form Enrolment Day", and that is also the date AQA gives for the release of June 2026 GCSE results: "Results day for the June 2026 exam series is: 20 August 2026." Results slips reach students from 8.00am.

Enrolment runs on a strict split timetable. Current CSGS students "are required to re-enrol on Thursday 20th August between 8.15am and 9.30am to confirm your Year 12 subject choices". External applicants have a separate window: they "are required to submit their enrolment request on Thursday 20th August between 10.00am and 5pm", entering their GCSE results, uploading a copy of the results slip, adding any certificates from earlier years and confirming final subject choices. Access to the system is embargoed until each group's window opens.

The cut-off carries a stated penalty: "Any enrolment requests received after 5pm will be deemed late and will not be included in the first offer round." That is roughly seven hours between collecting a results slip and completing a form that decides whether a place is confirmed in the first round — on a day when a family may also be weighing a grade that missed a subject threshold. The whole process is online, and the school asks applicants not to travel to the site. The enrolment page is then updated through the period "20th August to 28th August".

Two practical consequences follow. First, subject change requests are considered at enrolment, "eligibility and timetable permitting", so a candidate who misses the grade 8 needed for Mathematics has a same-day conversation to prepare for rather than a letter to await. Second, an applicant who did not apply in January can still submit an Enrolment Day application to join the waiting list by completing both the Application Form and an Enrolment Request — but they join behind everyone processed in the first offer round.

What Chislehurst and Sidcup Does Not Offer at 16

Curriculum at 16 is a live question in this borough, because the other selective co-educational sixth form in Bexley ran an International Baccalaureate Diploma programme and has now stopped. It is worth answering directly for this school: Chislehurst and Sidcup has no IB provision, no BTEC route and no T Level route. Its prospectus, its subject information booklet and its current study programme page describe A Levels, AS Levels and the Extended Project Qualification, and nothing else. The prospectus puts it plainly: "In our sixth form, students choose three A Levels from a broad range of subjects." The school's verified profile on its own application platform lists more than 55 courses, all at that level.

The shape of the programme is three A Levels plus one enrichment choice. Here the documents disagree again, and this time the school's website is ahead of its paperwork. The Entry Requirements sheet names four enrichment options — an AS Level in English Literature, Mathematics or Further Mathematics, or the EPQ. The current study programme page names five, adding AS Computer Science. The subject booklet also carries Computer Science in its AS section. Where the website and the booklet agree against the older sheet, the website is the safer guide.

A fourth A Level is possible but rationed: "Students must achieve at least six grade 7s if they wish to be considered for four A Levels." That is a demanding threshold, and it sits well above the general APS gate — six grade 7s across seven subjects gives an average of at least 6.86 before the seventh grade is counted.

Two closing rules deserve emphasis because they remove options families sometimes assume exist. "There are no new admissions into Year 13 of the Sixth Form", so 16+ here is a single annual entry point with no mid-course transfer in. And "It is not the school's policy to allow students to repeat Year 12 or Year 13; the school's Sixth Form education lasts for two years." A student who struggles in Year 12 cannot restart it at this school. All Year 13 students must carry a minimum of three subjects.

On outcomes, the school reports that 81% of students went on to university, of whom 63% went to Russell Group institutions and 37% to other UK universities, with 11% taking a gap year and 8% moving into higher apprenticeships or employment. A separate page on the same website gives 66% for Russell Group, counted as a share of offers rather than of entrants, so the two figures measure different things and neither is a correction of the other. Families comparing selective sixth forms across the Kent border, such as Dartford Grammar School, should check which denominator each school has used before treating any two percentages as comparable.

Chislehurst and Sidcup Grammar School is recorded on the Department for Education's register as an academy converter in Bexley, URN 137423, teaching ages 11 to 18, mixed sex. Its 11+ route, which uses the Bexley Selection Test and a distance-driven oversubscription list, is covered separately in our guide to Chislehurst and Sidcup Grammar School 11+ entry.

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