The International Baccalaureate in the UK: a complete guide for international families

Your child is strong across the board: good at maths, but just as engaged in history and a second language. You are weighing UK Sixth Form options, and two qualifications keep coming up: A-Levels and the IB. The prospectuses assume you know the difference, the entry pages quote scores you cannot decode, and you are not sure which schools on your shortlist teach the IB. This guide explains how the International Baccalaureate works in British schools, what its results are worth to universities, and whether it suits your child.

What the International Baccalaureate is, and where it sits in UK schools

The International Baccalaureate is a family of academic programmes run by the International Baccalaureate Organisation, a non-profit foundation based in Switzerland and founded in 1968. It runs four programmes by age.

The earlier three cover the primary and middle years; the one parents researching UK Sixth Form usually mean is the senior, university-facing stage, the Diploma Programme (DP): a two-year course for students aged 16 to 19, taught in Years 12 and 13, the same stage at which most British pupils sit A-Levels.

In the UK, the IB is mainly an independent-sector qualification. Just over 100 schools across the country are authorised IB World Schools, and roughly 85 of those teach the Diploma. That is a small fraction of the several hundred schools offering A-Levels.

The gap matters for shortlisting: an International Baccalaureate UK placement means choosing from a narrower field, weighted towards international schools and a handful of well-known boarding schools.

The picture is also shifting. In October 2025 the government confirmed it will withdraw funding for the IB Diploma in state schools from the 2026/27 academic year, affecting the 20 or so state schools and several thousand pupils who currently take it. Existing cohorts can finish, but new state-funded places will not continue, which pushes the IB further towards the fee-paying sector.

For families getting their bearings, our guide to the UK education system sets out how independent, state and grammar schools fit together.

How the IB Diploma is structured: six subjects and the core

The Diploma’s defining feature is breadth. Where an A-Level student narrows to three subjects, an IB student studies six at once, taken across six subject groups. Three are studied at Higher Level (HL, the more demanding tier) and three at Standard Level (SL). On top of the subjects sit three compulsory core elements that no A-Level student is required to complete.

The six subject groups

Each student takes one subject from each group, which keeps the academic range deliberately wide:

• Studies in language and literature — the student’s strongest language.
• Language acquisition — a second language, from near-beginner to advanced.
• Individuals and societies — history, geography, economics, psychology and similar.
• Sciences — biology, chemistry, physics or computer science.
• Mathematics — taken at a level matched to the student’s intended direction.
• The arts — visual arts, music or theatre; this group may be swapped for an extra subject from another group.

The HL and SL split is where a family shapes the Diploma to the child. A future engineer takes mathematics and physics at Higher Level; a linguist weights the languages and a humanity. The three Higher Level choices are the ones selective universities scrutinise most closely.

The core: Theory of Knowledge, the Extended Essay and CAS

Theory of Knowledge (TOK) is a course in how we know what we claim to know, assessed by an essay and a presentation. The Extended Essay (EE) is a 4,000-word piece of independent research on a topic the student chooses, closer to a first taste of university work than anything else in the school timetable. Creativity, Activity, Service (CAS) requires sustained involvement in the arts, physical activity and community work outside the classroom.

That combination is the entire point of the Diploma. A student leaves at 18 with a language, a science, mathematics and a humanity still in hand, plus a genuine research essay and a record of activity beyond exams. It is demanding work, and it is not designed for a child who wants to drop everything except their three best subjects.

How IB scoring works: the 45-point scale

Each of the six subjects is graded from 1 to 7, with 7 the top mark. Six subjects therefore carry a maximum of 42 points. The TOK essay and the Extended Essay are graded together on a matrix that adds up to three further points, which is how the headline maximum of 45 is reached.

Two rules surprise parents. CAS earns no points, yet a student cannot pass the Diploma without completing it. And a failing grade in either TOK or the Extended Essay fails the whole Diploma, however strong the six subject grades are. The core is not a soft extra; it is a genuine condition of the award.

For a sense of scale, the IB reported a global Diploma pass rate of 81.9% in the May 2025 session, with more than 83,000 diplomas awarded worldwide. UK schools tend to score well above the global average, and the strongest British IB schools posted cohort averages around 36 points in 2025.

A score in the mid-40s is rare anywhere; at most schools, only a handful of students reach it in a given year. For most strong applicants, a realistic target sits in the high 30s, which already opens the door to leading universities.

How International Baccalaureate UK results reach the world’s universities

This is where many international families are misled by old information. Since 2017, the UCAS tariff — the points system UK universities use to compare qualifications — has scored the IB by individual component, not by the total Diploma score. Each Higher and Standard Level grade carries its own value on the official UCAS tariff: an HL grade 7 is worth 56 points, the same as an A* at A-Level, and Standard Level grades are worth roughly half.

The figure of “45 points equals 720 UCAS points” still circulates in school guidance packs, and it has been obsolete for years. The more important point is that the most selective universities barely use the tariff at all.

Russell Group institutions, including Oxford, Cambridge, Imperial, UCL and LSE, make conditional offers directly in IB points with named Higher Level requirements. A typical Oxford offer reads “39 points including 7,6,6 at Higher Level”; the equivalent UCAS number is never consulted. Universities value the Diploma’s research and independent-study demands, and admissions tutors often read the Extended Essay as a signal of readiness for degree-level work.

As a rough guide, a total around 36 points is broadly comparable to AAA at A-Level. But for a competitive course, the named HL grades matter far more than the headline total. A 39 with Higher Level grade 6 in mathematics will not satisfy a “Higher Level mathematics 7 required” condition, however strong the overall score looks on paper.

IB or A-Levels: which suits your child

Neither qualification is better in the abstract; they reward different students. A-Levels let a child go deep on three subjects and drop the rest, which suits a student who already knows they want medicine, or engineering, or law. The IB keeps every door open for two more years, at the cost of a heavier and more varied workload. The table below sets out the practical differences; for a fuller treatment, see our dedicated comparison of A-Levels and the IB Diploma.

One practical caution weighs against the IB for some students. A child whose English is still developing carries it across six subjects and a 4,000-word essay, not three. The breadth that makes the Diploma valuable also makes it unforgiving for a student stretched thin. That is a question of fit rather than ability, and it is worth being honest about before committing.

What it costs to study the IB in the UK

Because the IB in the UK is almost entirely an independent-school qualification, the cost is simply the cost of an independent-school place. There is no separate IB fee as such. Two figures shape the budget, and both moved sharply in 2025.

Since 1 January 2025, all UK private school tuition and boarding has carried 20% VAT under the Finance Act 2025, which raised most bills by 12% to 16% once schools absorbed part of the increase. Fees also rise with age, so Sixth Form, where the IB is taught, sits at the top of the scale.

As a working guide for the 2025/26 academic year, UK day school fees average around £19,000 per year and boarding around £50,000, with the most selective schools well above that. London’s IB-specialist international schools run higher still: tuition at Diploma level commonly reaches £35,000 per year, and once registration, transport, lunches and the usual extras are added, an all-in figure of £42,000–£48,000 for a senior-school place is realistic. Always confirm whether a quoted fee already includes VAT before comparing schools.

Many IB schools also offer academic scholarships and means-tested bursaries, which are worth raising with the admissions office at the point of registration.

Choosing an IB school and when to apply

The narrower field of IB schools changes how a shortlist comes together. With fewer than 100 Diploma schools nationally, geography, boarding availability and academic fit narrow the list quickly, and the strongest IB schools are competitive at 16+ entry. Demand for the best-known IB sixth forms is high, and they tend to fill their places early in the cycle.

Entry at 16+ and what schools look for

Most families apply a year to 18 months ahead of the intended September start, which leaves room for assessment, interview and a school visit before committing. At 16+, a Sixth Form admissions team is reading for two things: strong GCSE or equivalent grades in the subjects a child intends to take at Higher Level, and the organisation to carry six subjects plus the core.

Some schools also ask for a short admissions assessment, or a conversation about why the child wants the breadth of the Diploma rather than the focus of A-Levels.

Fit matters more than prestige here. The IB rewards self-motivated students who can hold several subjects and an independent essay in balance at once. A child who thrives by going deep on a few favourites may be happier, and may perform better, on A-Levels at the same school. For families weighing the timing of a move into the British system, our guide to the best age to enrol in a UK school sets the decision in context.

When the IB is the right choice, and how EDVISION helps

For the genuine all-rounder, the IB Diploma is an excellent fit: a student who is reluctant to give up the sciences or the languages at 16, who works steadily, and who values a globally portable qualification recognised by universities in more than 140 countries.

For the committed specialist with a clear university course already in mind, A-Levels at a strong school often serve better. The right answer depends on the child, not on which qualification sounds more impressive.

EDVISION’s role is to make that judgement with you, then act on it. That means matching a child’s profile to schools that teach the IB well, setting honest expectations about score bands and entry requirements, and building the application around shortlist, references, interview preparation and, where needed, guardianship.

We do not promise admissions outcomes, because no responsible adviser can. What we do is make sure the choice between the IB and A-Levels is made on the right grounds, at the right school, with the right preparation behind it.

If your child is approaching Sixth Form and you want a clear view of whether the IB fits, an EDVISION adviser can talk the options through with you.