The 13+ is not one exam. It is a process — and the parts of it happen years apart. If you have found the online explanations confusing, that is not a failing on your part. The system genuinely is layered, the layers were built in different decades, and schools use different combinations of them. Worse, much of what is published about it is out of date, because the system has been shifting under everyone's feet for the past decade.

Here is the whole landscape in one piece. Once you can see the three layers and what each one is for, every school's individual arrangement becomes readable.

The route in one paragraph

A child on the 13+ route joins an independent senior school at the start of Year 9, aged 13. The decision about whether they get a place is usually made much earlier, off a pre-test sat in Year 6 or Year 7 — most commonly the ISEB Common Pre-Test, sometimes a school's own equivalent. What follows the pre-test is a conditional offer. The condition is typically satisfied in Year 8, either by sitting Common Entrance (a set of subject exams written by ISEB, the Independent Schools Examinations Board) or by the school's own papers — and at some schools, by nothing more than continuing to work well at their current school.

Three layers: pre-test, offer, confirmation. Everything else is variation.

Who this route is for

The 13+ is overwhelmingly a route into independent senior schools — day and boarding — most of which begin their main intake at Year 9. It is the traditional destination of the prep school system: prep schools run to the end of Year 8 precisely because their pupils leave at 13.

That said, plenty of 13+ candidates are not at prep schools. Children at state primaries and state secondaries apply too; they sit the same pre-tests and, where required, the same exams. The route is open — it just wasn't designed around them, so their families do more of the navigation themselves. If your child is in Year 5 or 6 at a state school and you are weighing this against grammar school entry at 11, that is a real decision with its own trade-offs, and it deserves its own article — see the piece on choosing between 11+ and 13+ entry.

Layer one: the pre-test (Year 6 or 7)

The first formal assessment most 13+ candidates meet is the ISEB Common Pre-Test: an online, adaptive, multiple-choice test covering English, mathematics, verbal reasoning and non-verbal reasoning. Two things about it matter more than anything else:

  1. It is sat once, and the result is shared. A child sits the pre-test a single time in an academic year — usually at their own school — and every senior school the family has registered with can see the result. Your child does not sit a separate pre-test for each school on your list, unless a school runs its own test instead of (or on top of) ISEB's.
  2. It is where most of the selection actually happens. For many schools the pre-test result, alongside a report from the child's current school and often an interview, is the substance of the decision.

Some schools use their own assessments instead of, or in addition to, the ISEB test. The format varies; the function is the same — an early sift, years before entry.

The pre-test deserves a fuller treatment than a paragraph, particularly the word "adaptive", which worries parents far more than it should. That is its own article.

Layer two: the conditional offer

If the pre-test, the school report and any interview go well, the school makes an offer — usually during Year 7, sometimes late in Year 6. It is almost always conditional: the place is your child's provided they meet the school's stated requirement between now and entry.

The condition varies by school, and this is where families most often lose the thread:

  • "Pass Common Entrance" — the traditional condition. The school states a threshold (each school sets its own) and your child sits CE in Year 8.
  • "Sit our own papers" — the school sets its own Year 8 exams, in fewer subjects than CE, marked internally.
  • "Maintain progress" — a report-based condition; the school wants continued good work and conduct, evidenced by the current school's reports, with no further exam.

Read the offer letter closely. The condition it states is the only one that applies to your child, whatever a forum thread says about "what schools do".

Layer three: Year 8 — Common Entrance or the school's own exams

Common Entrance at 13+ is a suite of subject exams — English, mathematics and science at the core, with humanities and languages beyond — written centrally by ISEB but marked by the receiving senior school, which also sets its own pass threshold. The main sitting is in the summer term of Year 8, close to the end of prep school. It is a genuine set of exams across a genuinely wide curriculum, and it is covered subject by subject in what CE actually consists of.

The strange-sounding truth, though, is this: by the time a child sits CE, the place is usually already theirs in every practical sense. Selection happened at the pre-test. CE confirms the offer, keeps Year 8 academically honest, and — for the prep schools that still build their curriculum around it — provides the scaffolding for two years of teaching. Children do occasionally miss their threshold, and schools handle that in different ways (a conversation with the prep school head is almost always part of it), but CE is not, for most candidates, a second round of selection.

A growing number of senior schools have dropped the CE requirement altogether, which is a story about institutional change worth understanding on its own terms — why schools moved away from CE covers the dynamic. The practical consequence for you is simply that layer three looks different school by school: full CE at one, three internal papers at another, a progress condition at a third.

Why the system feels backwards

Most exam systems put the exam at the end and the decision after it. The 13+ does the opposite: the decision comes first (pre-test, Year 6/7) and the biggest exams come last (Year 8), after the decision has largely been made. Once you see this, two common parental confusions dissolve:

  • "Why is my ten-year-old being tested for a school she won't join until she's thirteen?" Because senior schools want to settle their lists early, and prep schools want certainty about where their pupils are heading. The pre-test is the early sift that makes both possible.
  • "If the place is already offered, why does Year 8 still end in serious exams?" Partly to keep the condition meaningful, partly because prep schools value the structure, and partly because arriving at a demanding senior school having coasted through Year 8 serves nobody — least of all the child.

Variations you will meet

The three-layer picture covers most cases. The variations worth knowing about:

  • Schools without a Year 8 exam. The offer is effectively firm once made, subject to reports and conduct.
  • Scholarship routes. Academic scholarship candidates typically sit harder, separate papers in Year 8 — often the school's own or ISEB's Common Academic Scholarship Examination — on a different track from the standard entry exams.
  • 11+ entry to 13+ schools. Some senior schools also admit at Year 7, or assess at 11 for deferred entry at 13. If you are looking at a school like this, its admissions page will describe a hybrid of the two systems.
  • Occasional places. Families arriving outside the main cycle — relocations, moves from abroad — are usually assessed with the school's own papers at whatever point they apply. The three-layer timetable does not apply; the school's registrar is the person to call.

What this means for planning

Three practical conclusions fall out of the structure:

  1. The early years matter more than the exam years. The consequential assessment is the pre-test, in Year 6 or 7 — so the calm, steady building of core English and maths through Years 5 and 6 matters more than any Year 8 heroics. The full timeline from registration to Year 9 lays this out year by year.
  2. The receiving school's own admissions page is the only authority. Requirements differ school to school and change year to year. Any general article — this one included — describes the system, not your school's current policy.
  3. Year 8 still deserves respect. Whether it ends in CE, internal papers or nothing formal, the habits a child carries into a senior school are built in Year 8. Treat it as preparation for Year 9, not a victory lap.

For what it is worth, this is also where we sit as a product: our tutors teach the KS3 curriculum — the maths, English and science that the pre-test's curriculum sections and the CE core draw on — and a family can set the exam and its date so that every session and weekly plan works backwards from it. What we do not do is verbal or non-verbal reasoning; those sections of the pre-test are not something we prepare children for, and we would rather say so plainly than imply otherwise.

FAQ

What is the 13+ in one sentence?

13+ is entry to a UK independent senior school at the start of Year 9, age 13, usually decided by a pre-test sat in Year 6 or 7 and confirmed by exams — Common Entrance or the school's own papers — sat in Year 8.

Is the 13+ one exam?

No. It is a process with up to three assessment layers: the ISEB Common Pre-Test (or a school's own pre-test) in Year 6/7, sometimes an interview and further assessment in Year 7, and then Common Entrance or school-set papers in Year 8. Not every school uses every layer.

When does selection actually happen for 13+ entry?

Mostly at the pre-test stage, in Year 6 or 7. For most schools the conditional offer that follows the pre-test is the real decision; the Year 8 exams confirm it rather than re-open it.

Does my child need to sit Common Entrance?

Only if a school holding their offer requires it. Some senior schools still do; others have replaced it with their own papers or dropped a final exam requirement entirely. The receiving school's admissions page is the only reliable answer.