SEC 2027 explained: what replaces the O-Level, and the G1/G2/G3 levels

If your child is in Secondary 2 or 3 right now, you have probably heard that the O-Level is being replaced in 2027 — and then run into a wall of acronyms. SEC, Full SBB, G1, G2, G3. Clear answers are surprisingly hard to find, so here is the whole change in one place: what the Singapore-Cambridge Secondary Education Certificate (SEC) actually is, what the G1/G2/G3 levels mean, how grading changes, what is happening to Mother Tongue, and — the question every parent really asks — exactly which cohort is affected first.

What is the SEC, and what does it replace?

From 2027, the separate GCE O-Level, N(A)-Level and N(T)-Level certificates are merged into a single national certificate: the Singapore-Cambridge Secondary Education Certificate (SEC). It is still co-certified with Cambridge, just as the GCE was.

The reason for the change is Full Subject-Based Banding (Full SBB). The old Express / Normal (Academic) / Normal (Technical) streams are gone. A student is no longer "an Express student" or "an N(A) student." Instead, every student takes each subject at a level that fits that subject, and the SEC certificate lists every subject next to the level it was taken at. One student, one certificate, a mix of levels.

What do G1, G2 and G3 mean?

The G stands for General, and the number is the level of demand:

• G3 — set at the current O-Level standard. This is the level most academically inclined students will take for most subjects.
• G2 — set at the former N(A)-Level standard.
• G1 — set at the former N(T)-Level standard.

The point of Full SBB is that these are chosen per subject. A student strong in the sciences but finding a second language harder might take Physics and Chemistry at G3 and Mother Tongue at G2. There is no single label for the student — only a level for each subject.

Who is the first SEC cohort? (Is my child affected?)

This is the part that causes the most worry, and it is actually simple once you anchor it to the 2027 sitting:

• The first students to sit the SEC are the Secondary 4 cohort of 2027.
• That means students who are in Secondary 3 in 2026 are the first SEC cohort — they move into Sec 4 in 2027 and sit the new exam.
• Students in Secondary 4 in 2026 are not affected. They sit the final GCE O-Level in 2026 under today's rules. (See our O-Level revision guide for that cohort.)

So if you are a Sec 2 or Sec 3 parent in 2026, your child is on the SEC track. If your child is in Sec 4 in 2026, nothing about their exam changes.

How is the SEC graded?

Grading deliberately stays aligned with the old standards, which is why this part is less disruptive than the name change suggests:

• G3 subjects keep the O-Level mapping — A1, A2, B3, B4, C5, C6, D7, E8 and 9. An A1 at G3 means what an A1 means at O-Level today.
• G2 and G1 subjects use numerical bands — Grade 1 to Grade 6 — matching the former N(A)- and N(T)-Level scales.

The single SEC certificate shows each subject's grade next to its level, so a reader can see both what was achieved and at what demand. Post-secondary admission (junior college, polytechnic, ITE) continues to use aggregate scores built from these grades; check the year's official cut-off rules on the MOE and SEAB sites as they are confirmed for the 2027 cohort.

What is changing with Mother Tongue?

One concrete exam-logistics change matters for revision planning: the mid-year (June) Mother Tongue written examination is being removed. Under the SEC, the written Mother Tongue paper is sat once a year, in the common September examination window, alongside English — and there is no separate second sitting to fall back on.

Practically, that removes the "I'll re-attempt in the second sitting" safety net and makes steady, year-round revision of vocabulary, characters and tones more important than ever. Our guide to memorising 听写 and Mother Tongue vocabulary covers exactly the kind of spaced routine that suits a single annual paper.

The reassuring part: what you memorise doesn't change

Here is the line to hold on to through all the new vocabulary. G3 papers are set at the same standard as today's O-Level papers. The format and certificate are changing; the content you must commit to memory is not.

A Chemistry definition, the reactivity series, a History case-study fact, a Maths identity, a Geography statistic — these are identical whether the paper at the end is called O-Level or SEC G3. That means any revision work you start now is not wasted when the system flips in 2027. A subject deck built in Sec 3 in 2026 is already valid 2027 G3 material.

This is also why the change rewards starting early rather than waiting for the "new" syllabus. The fundamentals are stable; only the wrapper is new.

How spaced repetition fits the transition

The SEC keeps the thing the Singapore system has always demanded: two-plus years of content that the final paper can draw on freely. Cramming holds that for a week; only spaced review keeps it retrievable in the exam hall. Two well-established findings underpin this — active recall roughly doubles week-later retention versus rereading, and spaced repetition schedules those self-tests so a fact learned in Sec 3 survives to the Sec 4 paper. Neither depends on what the certificate is called.

How Memor More fits SEC revision

Memor More is a free flashcard app built on active recall and spaced-repetition scheduling, which makes it a natural fit for the transition specifically because decks survive the change:

• One deck, both systems. A subject deck built for the O-Level standard is already valid G3 material — the same deck carries a student straight across the 2027 cohort boundary.
• Shared decks across the cohort. An older sibling's O-Level Chemistry deck, or a tutor's deck, can be shared with a Sec 3 student on the SEC track without rebuilding anything. Build once, reuse across the change.
• AI-assisted card creation turns a page of notes or a definitions list into a deck quickly, so covering six to nine subjects stays manageable.
• Audio on cards supports the single annual Mother Tongue paper — characters, tones and oral phrases, not just the written form.
• Ready-made decks to start now: the free O-Level Chinese 成语: Essential Idioms deck and the Singapore General Knowledge & National Education deck are valid for both O-Level and SEC G3 students.

It is free, runs on iPhone, iPad and Mac, and keeps decks on your device. It does not replace understanding or practice papers — it handles the recall layer with the methods the research supports, and it does so in a way that is ready for both the O-Level and the SEC G3.

Download Memor More on the App Store

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Further reading

• O-Level revision with spaced repetition: a study plan that beats cramming
• A-Level revision: H1, H2 and GP
• Spaced repetition for Singapore students: PSLE to A-Level
• Memorising Chinese 听写 and Mother Tongue vocabulary
• PSLE 2026 memorisation guide for parents
• What is active recall? A science-backed explanation
• Spaced repetition: what 130+ years of research actually shows