UPSC Prelims Answer Key: Provisional Key, Final Key and How to Challenge

The UPSC prelims answer key is the list of the answers UPSC accepts as correct for each question of GS Paper I and CSAT. From CSE 2026, UPSC publishes it twice: a provisional key within days of the exam, which candidates can challenge, and the final key after the final result. For the prelims held on 24 May 2026, UPSC announced the release of the provisional key on 27 May 2026.

This page explains both keys and how to raise a challenge, from UPSC's notice and its press releases. It does not reproduce any answers: use UPSC's own key.

Why there is now a provisional key

Until CSE 2025, UPSC published the prelims answer key only once, after the whole examination was over. Its press note on the CSE 2025 prelims result says the marks, cut-off marks and answer keys would be uploaded only after the final result.

That changed for CSE 2026. In a written reply in the Rajya Sabha on 23 March 2026, the Government said that, in compliance with the Supreme Court's judgment in W.P. (C) No. 118/2024, UPSC had framed guidelines to release a provisional answer key after the preliminary examination, from the Civil Services (Preliminary) Examination 2026 onwards and for all its structured examinations. UPSC announced on 18 May 2026 that it would do so "for the first time", and on 27 May 2026 that it had released the key.

How to challenge the provisional key

Representations go only through UPSC's Online Question Paper Representation Portal (QPRep), on upsconline.nic.in. The rules come from the CSE 2026 notice and UPSC's release of 27 May 2026:

1. Use the window. The notice gives five days, from the third day after the exam to 6 PM on the seventh day. For the CSE 2026 prelims of 24 May, that meant until 6 PM on 31 May 2026. Nothing is accepted after the window closes.
2. Use the portal only. UPSC accepts no representation by email, post or hand, and does not reply to correspondence about it.
3. Back it up. For each question, state the answer you believe is correct, with a brief explanation and supporting documents from three authentic sources.

The portal also takes representations on the question papers themselves, for example on a question you think is wrongly framed. Every representation is placed before subject experts, who examine it and the documents before the key is finalised.

A practical point: a representation is only as strong as its sources. UPSC's release says its questions can be traced to standard textbooks, journals, Government websites, Government press releases and reputed newspapers, so cite sources of that kind rather than a coaching answer sheet.

The final answer key

The final key comes later, with the prelims marks and cut-offs. UPSC's release of 27 May 2026 says the final answer key will be released only after the declaration of the final result, in line with its existing practice, and the press note on the CSE 2026 prelims result says the same about marks, cut-off marks and answer keys. Answer keys appear on UPSC's Answer Keys page.

Using the key to estimate your score

You can use the provisional key to estimate your score while you wait for the result:

• Count GS Paper I and CSAT separately. CSAT only has to reach 33%; your GS Paper I score is the one compared with the cut-off.
• Apply negative marking. Each wrong answer costs one-third of that question's marks, and two answers to one question count as wrong. The prelims score calculator does the arithmetic, and the negative marking guide explains it.
• Compare with past cut-offs. The cut-off checker compares a GS Paper I score with every official prelims cut-off since CSE 2016. Remember that the provisional key can change and that nobody knows the CSE 2026 cut-off until UPSC publishes it.

The prelims result itself is a list of roll numbers; how each result is announced is explained in UPSC result, and the year-wise lines are on the prelims cut-off page.