Do Sixth Form Mock Results Decide Your Place in 2027?

A school sixth form may legally set academic entry criteria — including a required GCSE mock or predicted grade — because it is one of only three categories of state school in England permitted to select by ability, under the School Admissions Code 2021. Four specific rules limit that power, and in July 2022 the Schools Adjudicator upheld part of one objection over a school's own predicted-grade arrangements, case ADA3899, without ruling on the wider question.

Can a Sixth Form Actually Use Your Mock or Predicted Grades? What the Law Says

The starting legal position surprises many parents. Two parent-forum threads found during this research state flatly that it cannot be done — one telling a poster that a state secondary school ‘restricting offers based on predicted grades because they are subjective... would be a breach of the admissions code’ — and both are wrong. A school sixth form is allowed to select applicants by academic ability, including by mock or predicted grade, and doing so is not a breach of anything.

The School Admissions Code 2021, the statutory guidance every maintained school and Academy sixth form must follow, says so directly: ‘Admission authorities can, however, set academic entry criteria for their sixth forms, which must be the same for both external and internal places’ (para 2.6). A footnote to that paragraph explains why sixth forms are unusual at all: ‘There is a general restriction on selection by ability. Only the following schools are permitted to use selection by ability: designated grammar schools; schools with partially selective arrangements which already had such arrangements in place during the 1997/98 school year; and school sixth forms’ (footnote 20). Outside those three categories, no state secondary school in England may select pupils by ability at all — a school sixth form is one of a small, deliberate set of exceptions Parliament built into an otherwise comprehensive system, not an oversight.

The Four Rules That Actually Constrain a Sixth Form's Use of Your Grades

Permission to select academically is not an unlimited hand. Four specific requirements bind every school sixth form that uses mock or predicted grades, and none of the five pages already ranking for this question states any of them.

First, the criteria must be identical for internal and external applicants — a school cannot quietly demand a higher predicted grade from an outside candidate than it asks of its own Year 11 leavers, or the reverse (para 2.6). Second, a discussion meeting about a sixth-form application cannot itself decide the outcome: the Code states that while ‘a meeting may be held to discuss options and academic entry requirements for particular courses... this meeting cannot form part of the decision making process on whether to offer a place’ (para 1.9(m)) — so a place cannot turn on an informal conversation with no published process behind it. Third, looked-after children and previously looked-after children keep the highest priority in admissions even against an academic entry requirement (para 2.6). Fourth, a sixth form's admission arrangements for external applicants must be consulted on, formally determined and published to the same statutory annual timetable that governs entry to Year 7 — a school cannot set or change its sixth-form criteria informally, partway through a cycle.

For how a predicted grade is actually calculated in the first place — as distinct from how a sixth form is allowed to use it — see our separate guide to how predicted grades are set.

What Happens If a Sixth Form Gets It Wrong? The Schools Adjudicator, the 15 May Deadline, and the One Case on Record

Anyone who believes a school's admission arrangements — sixth form included — do not comply with the Code can object to the Schools Adjudicator, and the deadline falls on the same date every year: 15 May. An Adjudicator's decision ‘is binding and enforceable, and can only be challenged by judicial review in the High Court’ — there is no ordinary right of appeal against it.

Only one determination on record deals with predicted grades in any depth: ADA3899, decided 15 July 2022, concerning Twyford Church of England High School's sixth-form arrangements. It is worth reading precisely, because it already gets misquoted online in both directions. The Adjudicator did not rule that using predicted grades is unlawful in general — he said the opposite explicitly: ‘I leave to one side for present purposes the question of whether the use of “predicted grades” as part of the school's methodology is fair (or reasonable) or objective’ (para 50). What he did rule on was Twyford's own specific 2022 arrangements, in a school that had received 742 applications for 80 places that cycle: having examined exactly how those arrangements worked, he concluded ‘I do not consider that the use of “predicted grades” in this case is fair or objective’ (para 69), and ‘For those reasons I uphold that part of the objection which complains that the school's use of “predicted grades” in this case is contrary to paragraph 14 of the Code’ (para 70).

The distinction matters because Twyford's own current policy shows the direct, traceable result. For entry September 2027, its published arrangements state: ‘Predicted grades provided in the “Twyford Sixth Form Academic Statement” form will not be used to inform decisions on admission,’ with final decisions instead ‘made on National GCSE Results Day.’ The school still collects a mock grade, a predicted grade and a target grade on that form, for the kind of informal discussion meeting para 1.9(m) above says cannot decide anything — but the number the Adjudicator found unfair no longer decides a place.

What Nine Named Sixth Forms and Colleges Actually Ask For — And Which the Law Even Covers

Every one of the five pages already ranking for this question hedges with some version of ‘some sixth forms look at mocks, others don't’ and names not one real policy. The register below replaces that hedge with nine institutions' own current, published admissions arrangements, checked directly against each one's own website or prospectus rather than a summary of it.

It is worth knowing, before reading the table, which of these nine the Code above actually governs. Four of the nine — Woodhouse College, Hills Road Sixth Form College, Ada (National College for Digital Skills) and Saint Francis Xavier Catholic Sixth Form College — are registered with the Department for Education as stand-alone 16-to-19 providers: two as an ‘Academy 16-19 converter’, two as ‘Further education’. DfE's own guidance is direct about what that means: ‘The school admissions and appeals codes do not apply to special academies, alternative provision settings or stand-alone 16 to 19 institutions.’ The Code's own scope confirms it from the other direction — across 52 pages, it never once uses the phrase ‘sixth form college’ or ‘further education’. The remaining five — Tiffin School, St Olave's Grammar School, St John Payne School, Newstead Wood School and Twyford Church of England High School — are ordinary school sixth forms, so the four rules above bind them directly.

This register is not a national sample and does not claim to be one. It skews to London, the South-East and Greater Manchester, and to large, oversubscribed institutions with a public PDF prospectus — the kind of school most likely to have a detailed, searchable policy in the first place. No under-subscribed comprehensive and no independent (fee-paying) school's own published sixth-form policy is included; the independent-school angle below comes from a parent's own account, not a school's own document. For GCSE entry-grade thresholds at a specific grammar school, see our grammar school sixth-form entry requirements guide.

Source: each institution’s own published admissions policy or prospectus, linked above; DfE Get Information about Schools register for institution type.

The Real Cost of Getting This Wrong: A Lost Sixth-Form Place

The legal framework above is not academic. On Mumsnet, a parent described exactly how the gap between a mock grade and a genuine predicted grade cost their child a place. Their son's independent secondary school ‘don't give predicted grades, only their best mock grades’ — and his A-level maths course required a grade 7. His mock, sat with little revision, came out at a 6, and ‘the school are using his mock grade with no uplift’ as the figure it supplied to the sixth form. As the parent put it: ‘The school never told us what grades they would use nor what their policy is on using mock grades as predicted grades.’

That last sentence is the practical lesson underneath everything above. The Admissions Code discussed through this page governs how a receiving sixth form is allowed to use whatever figure it is given — it has nothing to say about how a pupil's own school arrives at that figure in the first place. The word ‘predicted’ does not appear anywhere in the Code's text, for a state school or an independent one. The only real protection available to a family is to ask the sending school directly, and early, exactly which number it will submit and how it is calculated, since no regulation obliges the school to volunteer it.

A second, separate Mumsnet thread shows a related confusion playing out for a different family: mixing up a school's internal Year 10 target grade with the predicted grade that actually goes on a sixth-form application. One reply states the distinction correctly: ‘End of KS4 target grades are not predicted grades. Do not put that down on the sixth form application.’ The two numbers are produced differently, for different purposes, and a family that submits the wrong one risks the same outcome as the lost place above. Exactly which grade belongs on that form is its own question, covered in full in our guide to target grade, mock grade or predicted grade: which one goes on the sixth-form form.

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