JEE Main 2027 Registration: 12 Mistakes That Can Cost You Your Attempt

Most JEE Main 2027 registration problems come from a handful of avoidable mistakes: a name or date of birth that does not match your Class 10 certificate, a wrong photo, an invalid category certificate, poorly chosen exam cities, or filling two forms. NTA gives only one short correction window, and some fields cannot be fixed at all.

This guide lists 12 real mistakes, each checked against the JEE Main 2026 Information Bulletin and NTA's 2025-26 notices. The 2027 bulletin is not out yet, so we have marked where the rule may change.

When does JEE Main 2027 registration open?

NTA has not announced the JEE Main 2027 registration dates yet. Its exam calendar lists Session 1 on 22 to 24 and 28 to 30 January 2027. Last year, the Session 1 form opened on 31 October 2025 and closed on 27 November 2025, so expect a similar window in late October or November 2026.

That gives you a few weeks to prepare documents. Use them. Every mistake below is easier to prevent before the form opens than to fix after it closes. The full timeline is in our JEE Main 2027 exam date and registration guide.

Mistake 1: Is your name or date of birth different from your Class 10 certificate?

This is the most serious mistake. The JEE Main 2026 bulletin says your score card is generated as per your name in the Class 10 certificate or mark sheet. NTA's September 2025 advisory also asked students to update Aadhaar with the correct name and date of birth as per the Class 10 certificate.

Common problems include a missing surname, initials instead of a full name, spelling differences like "Kumar" and "Kumaar", and a different date of birth in Aadhaar. These mismatches can cause trouble at the exam centre and later at JoSAA document verification, where your Class 10 mark sheet is used as proof of date of birth. Get your documents ready now with our Aadhaar and certificate checklist before JEE Main 2027 registration.

Fix Aadhaar first through UIDAI, and then fill the JEE form exactly as your Class 10 certificate reads.

Also readJEE Main Chemistry Chapter-wise Quiz: Physical and Organic

Mistake 2: Can you change your name after Aadhaar authentication?

In the 2026 form, candidates could verify identity through Aadhaar e-KYC with an OTP. The Aadhaar page in the 2026 bulletin carried a clear warning: the system will not allow you to change the name after Aadhaar authentication. So check every letter before you click submit.

The OTP goes to the mobile number linked with your Aadhaar. If that number is old or belongs to someone who is not available, update it in advance. Candidates who used other ID proofs instead of Aadhaar or DigiLocker had to upload that ID as a JPG of 10 kb to 200 kb.

Mistake 3: What photo and signature size does NTA accept?

Your photo must be a recent colour passport-size photo, with about 80% of your face visible including ears, without a mask, on a white background, in JPG between 10 kb and 200 kb. The 2026 correction window did not allow the photograph to be changed, so a bad photo stays for the whole session.

The form also captures a live photograph through a webcam or phone camera, for which NTA asked for a light background, proper lighting and 80% face visibility including ears. Here are all the 2026 upload specifications in one place.

Keep a few printed copies of the same photo. The 2026 admit card instructions asked candidates to bring a passport photo that is the same as the one uploaded in the form.

NTA's bulletin warns that using someone else's photo, signature or certificate, or a morphed photo, is treated as unfair means. Upload only your own, recent, unedited images.

Mistake 4: What happens if you fill two JEE Main forms?

NTA's 2026 notice said that under no circumstances will a candidate be allowed to fill more than one application form. Multiple forms lead to cancellation of the result and are treated as unfair means, and action can be taken even at a later stage.

Students often create a second form because they forgot the password or made an error in the first one. Do not do this. The password can be reset through your security question, an SMS code on your registered mobile, or an email link. Errors should be fixed in the correction window.

Also readJEE Mains 2027 Registration & Notification: Status on 11 Oct 2026

Mistake 5: Whose mobile number and email should you use?

NTA's notice asks that the email and mobile number in the form are your own or your parents' only, because all communication is sent there. In the 2026 correction window, the mobile number and email address could not be changed at all.

Create your own password following NTA's policy (8 to 13 characters, with upper case, lower case, a number and a special character) and do not share it. The bulletin says neither NTA nor NIC is responsible for misuse of a shared password. Many students let cyber cafes or agents fill their form and then cannot log in months later for the admit card.

Mistake 6: How do you choose JEE Main exam cities?

In 2026, you could choose up to four exam cities, only within the states of your present and permanent address. The address itself could not be changed in the correction window, so a careless address locks you out of cities you actually want.

NTA tries to allot one of your chosen cities but can allot a different one for administrative reasons. The bulletin also says that if very few candidates choose a regional language at a city, you may be moved to another city. Pick your own city and nearby cities in order of priority, and choose the medium of the question paper carefully. Our JEE Main exam centre list shows the cities.

Mistake 7: Is your category certificate valid for counselling?

For OBC-NCL, your caste must be in the central list of OBCs, and creamy layer candidates must apply as General. The bulletin says OBCs only in the state list are not eligible for the reservation. The certificate is not uploaded with the JEE form, but it is checked in original at counselling.

If you claim a category you cannot prove at counselling, you can lose your seat. In the JoSAA 2026 document list for NITs and other institutes, EWS and OBC-NCL certificates had to be issued on or after 1 April 2026, or be government-issued, online-verifiable certificates valid till 31 August 2026 or the day of reporting, whichever was later. Expect a similar rule for 2027, which means you will likely need a fresh certificate after April 2027.

In the 2026 correction window, category could be changed. If your category changes the fee, NTA charged the difference, and it said fees would not be refunded in any case.

Mistake 8: Applying when your Class 12 year is not eligible

In 2026, only candidates who passed Class 12 in 2024 or 2025, or were appearing in 2026, could apply. If this pattern continues, JEE Main 2027 should be open to those who passed in 2025 or 2026 or are appearing in 2027. The 2027 bulletin will confirm this.

Your passing year is the year you first passed Class 12. The bulletin says an improvement exam does not count as a fresh first attempt. Also remember that the 75% rule for NIT and IIT admission is separate from exam eligibility. Read our JEE Main eligibility and 75% criteria guide before paying.

Mistake 9: Selecting the wrong state code of eligibility

Your state code of eligibility is the state from where you passed or are appearing in Class 12, not your home town or where you live. The bulletin's example: a student who studies in New Delhi but lives in Noida has Delhi as the state code, not Uttar Pradesh.

This matters because it decides your home state quota in NITs. NIOS candidates must choose the state where their study centre is located. If you appeared for improvement from another state, the state where you first passed is used. Read how home state quota changes your chances in our guide to NITs and IIITs for low JEE Main rank.

Mistake 10: Choosing the wrong paper

Paper 1 is for B.E./B.Tech and is also the route to JEE Advanced. Paper 2A is B.Arch and Paper 2B is B.Planning. If you want engineering, you must choose Paper 1. In the 2026 correction window, candidates could add a paper but the list did not include removing one.

Adding a paper increases your fee. In 2026, a General male candidate paid Rs 1,000 for one paper and Rs 2,000 for Paper 1 with B.Arch or B.Planning at centres in India. Here are the 2026 fees per session for one paper.

Processing charges and GST are extra. The 2027 fee will be confirmed in the new bulletin.

Mistake 11: Leaving fee payment to the last hour

Your form is complete only when the confirmation page is generated after successful payment. For JEE Main 2026, the Session 1 form closed at 9:00 PM on 27 November 2025, while fee payment was allowed until 11:50 PM. Payment gateways slow down near the deadline, and failed transactions are common.

The bulletin says that if the confirmation page is not generated after payment, the transaction is treated as cancelled and you have to pay again. Duplicate payments are reconciled by NTA after the final result and refunded. Pay early, then download and save the confirmation page as a PDF and a printout.

Mistake 12: What can you change in the JEE Main correction window?

The correction window is short, one-time and limited. In 2026, it ran from 1 to 2 December 2025, and after you submitted changes, the form was frozen. NTA said no correction would be entertained after that under any circumstances.

Here is what the Session 1 correction notice of 20 November 2025 allowed and blocked.

The bulletin also says NTA will not accept corrections by post, fax, WhatsApp, email or by hand. If a field is not open in the window, it simply cannot be changed.

Is APAAR ID mandatory for JEE Main 2027?

This is not confirmed yet. The 2026 application form had a separate APAAR ID step asking whether you have an APAAR ID, and media reports said it was optional. Keep your APAAR ID and DigiLocker login ready, and follow the 2027 bulletin, which may change this.

PwD candidates should also note that UDID details are verified from the government UDID portal. If you do not have a UDID card, the 2026 bulletin allowed you to upload a disability certificate, which NTA may verify with the issuing authority.

Registered already? Stay on track with our 100-day JEE Main 2027 study plan and the JEE Main 2027 Session 1 dates update.

What should you do next?

JEE Main 2027 registration is expected to open soon, and the best time to avoid these mistakes is before the form goes live. Use this checklist:

• Match Aadhaar name, date of birth and photo with your Class 10 certificate now.
• Make sure the Aadhaar-linked mobile number works for OTP.
• Scan photo, signature and Class 10 certificate in the right format and size.
• Use your own or your parent's mobile and email, and a strong password you do not share.
• Write down your state code of eligibility and four exam cities in order.
• Check your category status and plan a fresh EWS or OBC-NCL certificate for counselling.
• Fill only one form, pay early and save the confirmation page.
• Review every field carefully if you use the correction window.

Once the form is done, put your energy back into preparation. Our convert your percentile to rank helps you set a target score, and our pillar guide on colleges for low JEE Main rank shows what each rank band can realistically get you.