IMO registration 2026: last date, fees, and what happens if you miss it
By The Sophoz Curriculum Team
The short answer. SOF IMO 2026 runs on one of three dates: 23 October, 26 November or 10 December 2026. Registration costs ₹170 per student, inclusive of GST, plus up to ₹30 the school may add. There is no individual registration. SOF's own FAQ gives the deadline as "usually 30 days before the exam", which puts the three cut-offs at roughly 23 September, 27 October and 10 November 2026. If you miss all three, IMO is gone for this cycle, but several alternatives are still open into January 2027 and one of them accepts direct registration.
Most registration notices give you a date and stop. The useful part is what the process actually is, and what your options are once a deadline has passed, so both are covered below.
The three IMO dates and their implied deadlines
Schools choose one of the three offered dates. All students at a school sit on the same date.
| Exam date | Implied last date for registration |
|---|---|
| Friday 23 October 2026 | around 23 September 2026 |
| Thursday 26 November 2026 | around 27 October 2026 |
| Thursday 10 December 2026 | around 10 November 2026 |
An important caveat on that second column. SOF does not publish a fixed calendar date for registration closure. Its IMO FAQ states that a form will be accepted "if it reaches us before the last date of registration (usually 30 days before the exam)". The deadlines above are that rule applied to the published exam dates. They are a planning guide, not an official announcement, and the only authoritative date is the one SOF communicates to your school in the prospectus.
If you are close to a deadline, contact the school today rather than relying on the table. The school holds the actual form and the actual date.
What registration costs
| Item | Cost |
|---|---|
| SOF IMO registration | ₹170 per student, inclusive of GST |
| Optional school charge | up to ₹30 per olympiad, towards the in-charge honorarium and teacher remuneration |
| Realistic total per subject | ₹170 to ₹200 |
| School's cost to become a registered centre | Nil |
Three things worth knowing about the fee.
It is the same for all eight SOF olympiads. There is no per-exam differentiation, so IMO, ISO, IEO, ICSO, IGKO, IHO, ISSO and ICO all cost ₹170.
It is waived for students with major physical disabilities, and for Indian students whose parents were martyred in defence operations.
A widely-circulated figure of ₹125 to ₹150 is wrong. It appears on at least one prominent olympiad guide and contradicts SOF's own registration page. Where a reseller and the organising body disagree about the organising body's fee, use the organising body.
For students outside India, Bhutan and Nepal, SOF publishes two different numbers on its own site: US$11 plus an optional US$1 on the registration fee page, and USD 12 inclusive on the exam FAQ pages. The honest statement is US$11 base, up to US$12 all-in.
How registration actually works
Registration is through the school, and only through the school. SOF states plainly: "Students can register for the SOF IMO International Mathematics Olympiad through their respective schools only. Individual registrations are not accepted."
The sequence is:
- The school registers as an examination centre. SOF states that "any school can be registered as a center for SOF IMO Level 1" and that "no fee is required from the institution to become a registered examination centre". This is the step parents most often do not know exists.
- SOF sends a prospectus. "Prospectus containing the Registration forms are sent to all schools registered with SOF."
- The school collects student names and fees and returns the completed form to SOF by the due date.
- SOF sends admit cards and exam material to the school ahead of the chosen date.
- Results are declared within eight weeks of the examination.
There is no minimum number of students. This is the single most useful fact in this article for a small school, and SOF answers it directly in its FAQ. Asked whether a school with fewer than ten interested students can still enrol, SOF's answer is: "Yes."
Do not confuse this with the Level 2 qualifying rule, which does involve the number ten. That rule says a class topper qualifies for Level 2 where at least ten students from that class sat the exam and the topper scored at least 50 %. It is a criterion for advancing, not a threshold for registering. A school can enter three children.
Eligibility
Classes 1 to 12, with no academic bar. SOF states: "Students of classes 1st to 12th are eligible to appear for the 1st level Olympiads. There is no other eligibility criterion like minimum marks."
The syllabus is "the syllabus as prescribed by the CBSE, ICSE and various state boards", so no board is excluded and no board is privileged.
What happens if you miss the deadline
This is the part most notices skip, and there are more options than people assume.
Option 1: take a later IMO date
If you have missed the cut-off for 23 October, the 26 November and 10 December sittings are still open, subject to the school choosing that date. This is the first thing to ask the school, and it is often the whole solution.
The constraint is that the school picks one date for all its students, so this only works if the school has not already committed. A school that has locked 23 October cannot usually add a December sitting for three late entrants.
Option 2: take a different SOF exam later in the cycle
SOF's other olympiads run on their own dates, several of them well into 2027. If the point was for the child to sit a competitive paper this year rather than a mathematics paper specifically, these are still available:
| Exam | Remaining 2026-27 dates |
|---|---|
| SOF IEO (English) | 27 Oct, 17 Nov 2026 |
| SOF ISO (Science) | 30 Oct, 19 Nov, 3 Dec 2026 |
| SOF ICSO (Computer Science) | 17 Dec 2026 |
| SOF IHO (Hindi) | 23 Nov 2026, 22 Jan 2027 |
| SOF ISSO (Social Studies) | 30 Nov 2026, 19 Jan 2027 |
The same 30-day guidance applies to each.
Option 3: register directly with a body that allows it
This is the real answer for a family whose school does not participate at all, and it is why the individual-registration rule matters so much.
| Exam | Body | Fee | Registration | Date |
|---|---|---|---|---|
| NSTSE | Unified Council | ₹350 individual, ₹150 via school | Direct | 24 January 2027 online |
| CREST Mathematics (CMO) | CREST | ₹275 | Direct | 10-19 December 2026, slot booked |
| Unicus Global Maths (UGMO) | Unicus | ₹225 | Direct | 16-28 January 2027 |
| Unified Cyber Olympiad | Unified Council | ₹150 | Direct | 27 December 2026 |
| Indian Talent Olympiad | ITO | ₹500 individual | Direct | Registration sets close 10 Oct, 10 Nov 2026 |
NSTSE's 24 January 2027 online sitting is the most useful line in that table. It is a direct-registration date, months after IMO has closed, from a body that publishes a question-wise diagnostic report. It is a science-weighted paper rather than a mathematics one, with mathematics at ten marks out of sixty, so it is not a substitute for IMO in content. As a way for a child to sit a serious paper this year, it works. We have compared the two in IMO vs NSTSE.
CREST is the closest substitute in content, being a dedicated mathematics olympiad, fully online with a bookable slot, at ₹275 with two free practice tests included.
Option 4: treat it as a year off, deliberately
Worth saying, because it is often the right call and nobody says it.
If the deadline passed because the household was busy, that is information about capacity rather than about the child. An olympiad is ₹170 and an hour, and the preparation around it is eight weeks of structured work. Neither is worth doing badly under time pressure because a form was missed.
The eight weeks of mixed, spaced practice that would have preceded the exam are available regardless, they are free, and they are the part with a demonstrable effect. The free olympiad preparation stack sets out how to run it without an exam attached, and the child sits the paper next cycle already prepared.
A checklist for school coordinators
If you are the person at school handling this:
- Confirm the school is registered with SOF as a centre. No fee, and without it no prospectus arrives.
- Pick the exam date early, because it governs your internal deadline and you will want a fortnight of slack.
- Set your internal collection deadline two weeks before SOF's, not two days. Forms come back late.
- Do not turn away small numbers. There is no minimum; a class with three interested students can enter.
- Tell parents the ₹170 figure and any school charge separately, so the total is not a surprise.
- Flag the fee waivers for students with major physical disabilities and children of defence personnel who died in service.
- Note that ten students from a class sitting the paper is what opens the class-topper route to Level 2. Worth mentioning to a class that is close to it.
Frequently asked questions
What is the last date for IMO registration 2026? SOF does not publish a fixed calendar date. Its IMO FAQ states that forms are accepted if they reach SOF "before the last date of registration (usually 30 days before the exam)". With exam dates of 23 October, 26 November and 10 December 2026, that implies cut-offs around 23 September, 27 October and 10 November 2026. The authoritative date is the one in the prospectus sent to your school.
Can I register my child for SOF IMO directly? No. SOF states that individual registrations are not accepted and that students must register through their school. If your school does not participate, Unified Council's NSTSE at ₹350, CREST at ₹275 and Unicus at ₹225 all accept direct registration.
How much does SOF IMO registration cost in 2026? ₹170 per student, inclusive of GST, for India, Bhutan and Nepal. Schools may add up to ₹30 per olympiad, so parents typically pay ₹170 to ₹200. The fee is the same across all eight SOF olympiads and is waived for students with major physical disabilities and for children of defence personnel who died in service.
Is there a minimum number of students for a school to register for SOF? No. Asked directly whether a school with fewer than ten interested students can enrol, SOF's FAQ answers "Yes". The figure of ten students relates to a Level 2 qualifying criterion, not to registration.
What if my school does not conduct SOF olympiads? SOF is then unavailable, since it does not accept individual registration, but any school can register as a centre free of charge, so it is worth asking. Otherwise, NSTSE accepts direct registration at ₹350 with an online sitting on 24 January 2027, CREST at ₹275 runs 10 to 19 December 2026, and Unicus at ₹225 runs in January 2027.
What happens if I miss the IMO registration deadline? Ask the school first whether it has committed to a date, since the 26 November and 10 December sittings may still be open. Failing that, other SOF subjects run later in the cycle, and CREST, NSTSE and Unicus all accept direct registration with dates running into January 2027.
When are SOF IMO results declared? SOF states that results of its olympiads are declared within eight weeks of the examination.
Verified 21 September 2026 against sofworld.org, unifiedcouncil.com, crestolympiads.com and unicusolympiads.com. SOF publishes no fixed registration closing date; deadlines in this article are derived from SOF's own "usually 30 days before the exam" guidance and should be confirmed with your school.