Why Aadhaar Linking Fails Differently for Each Student

You are in the middle of linking Aadhaar numbers for 245 students. Student 47 — "Authentication Failed." Student 48 — "Aadhaar already linked to another student." Student 49 — no Aadhaar card at all. Student 50 — authentication succeeds but the system does not generate the APAAR.

These are four completely different problems. Each one has a different cause and a different fix. Treating all of them as "portal not working" and retrying the same steps causes the same errors to come back the next day — and the next.

This page covers the four specific errors that block student Aadhaar linking in UDISE+ 2026-27, what causes each one, and exactly what to do to resolve it — including what to do when the fix requires something outside the portal.

Error 1: Authentication Failed — Name Mismatch Between SDMS and Aadhaar

Aadhaar authentication in SDMS matches the student's name and date of birth against UIDAI records. If either does not match exactly, authentication fails. This is the most common cause of "Authentication Failed" — not a network problem, not a portal issue.

Common name mismatches:

• Initials vs. full name: SDMS has "R. Kumar" — Aadhaar has "Ravi Kumar." The initial does not match the full name in UIDAI's database.
• Spelling variation: SDMS has "Mohammed" — Aadhaar has "Mohammad." One letter difference fails authentication.
• Extra word: SDMS has "Priya Sharma" — Aadhaar has "Priya Devi Sharma." The middle name is missing from the SDMS record.
• Date of birth format or day/month swap: The operator entered the DOB as 07/08/2015 when the Aadhaar shows 08/07/2015 — day and month transposed.

Fix:

1. Get the student's physical Aadhaar card
2. Compare the name printed on the Aadhaar card character by character with what is in SDMS
3. Check the date of birth on Aadhaar against SDMS — confirm day, month, and year match
4. Request BRC unlock for the student's GP section
5. Update the name and DOB in SDMS to match Aadhaar exactly
6. Attempt the authentication again with the corrected data

Error 2: "Aadhaar Already Linked to Another Student"

This error means the Aadhaar number is already associated with a different SDMS student record. It already associates with a different student entry in three scenarios:

• Siblings' Aadhaar mixed up: two siblings in the same school, and the operator entered the older sibling's Aadhaar number for both during data entry.
• Student was enrolled twice in SDMS: An operator enrolled the student twice — once correctly and once as a duplicate entry. The first entry already links the Aadhaar. The second entry is the duplicate showing this error.
• Student transferred from another school: the old school linked the Aadhaar to their record at the old school. If you did not process the transfer correctly, the old record is still active with the same Aadhaar.

What you can do:

1. Note the student's Aadhaar number and name
2. Search SDMS for other students with the same Aadhaar number — identify which record the system links it to
3. If the other record is a duplicate: contact Block MIS Coordinator to merge or delete the duplicate
4. If the other record is at another school (transfer case): contact BRC to close the old school's record
5. Once you resolve the conflicting record, attempt the Aadhaar linking again

Error 3: Student Has No Aadhaar Card

Some students — particularly new Class 1 admissions and recently migrated students — do not have an Aadhaar card. Aadhaar is not available at birth; families typically enroll children between ages 3-6. If a student enrolled in Class 1 this year and the family has not yet gotten Aadhaar, there is nothing to link.

What you should do:

• Save all other data — complete the student's GP, EP, and SF sections in SDMS fully. Leave the Aadhaar field blank. Do not enter a parent's Aadhaar number as a substitute.
• Inform the family — Families can access Aadhaar enrollment for children at any UIDAI enrolment centre or Common Service Centre (CSC). The process takes 15-20 minutes. Once they enroll, UIDAI makes the Aadhaar number available for use within 7-10 days.
• Document pending cases — prepare a list of students with no Aadhaar: name, class, reason (new admission / recently migrated / applied for Aadhaar but have not received it). Submit this list to your Block MIS Coordinator before the data entry deadline.
• Link as soon as Aadhaar is received — once the family gets the Aadhaar, link it and generate the APAAR. Request BRC unlock if needed after data submission.

Error 4: Parent's Aadhaar Entry Instead of Student's

This mistake is more common than it appears. During data entry sessions where parents are present, the parent hands over their own Aadhaar card instead of the student's. The operator enters it without checking whose card it is. Authentication may succeed (since the parent's name and DOB are valid in UIDAI), but the system links the APAAR ID to the wrong person.

Signs of this mistake:

• Authentication succeeded but the name that appears after authentication does not match the student's name
• The date of birth that appears after authentication shows an adult birth year (e.g., 1985, 1990) instead of the student's year

Fix:

1. Do not save — if you notice during the session, cancel immediately before saving
2. If you already saved: request a BRC unlock for the student's SDMS record
3. Remove the incorrect Aadhaar number from the student's GP section
4. Get the student's own Aadhaar card — confirm the name is the student's, not a parent
5. Re-authenticate with the correct Aadhaar number and save

How to Track Which Students Are Pending

When linking Aadhaar for hundreds of students, you can easily lose track of who is pending and why. Before leaving each session, note the following details for each student whose Aadhaar you did not successfully link:

This list becomes your working document for follow-up. Submit a copy to your Block MIS Coordinator before the deadline—it shows what is pending and why, which protects you if the BRC questions incomplete APAAR counts.

Aadhaar Linking Checklist Before You Start

1. Collect physical Aadhaar cards for all students — do not rely on parents reading numbers aloud
2. For each student, verify the name on the Aadhaar card matches the name in SDMS before attempting authentication
3. Confirm the student (not the parent) is present or the parent has the registered mobile phone
4. Check uidai.gov.in to see the last 3 digits of the registered mobile — confirm the parent has that phone
5. Have the SDMS session open on a stable internet connection before starting OTP authentication
6. Do not attempt more than 3 OTP requests for the same Aadhaar in one session to avoid locking the account
7. After each successful linking, verify that the name that appears post-authentication matches the student's name

Written By

Pooja Sharma

Teacher & Contributor 🎓 BSc. (Physics), MSc. (Physics) and BEd.

Pooja Sharma is a qualified physics graduate (BSc, MSc) and certified teacher (BEd). As an active educator and contributor, she simplifies complex school portal processes, student registrations, and educational data entry tasks for academic administrators.