By ipomarket.in Editorial Team · Last reviewed: 2026-09-24
Disclaimer: This article is for informational purposes only and does not constitute investment advice. IPO investments are subject to market risks. Please read the offer document carefully and consult a SEBI-registered investment advisor before investing.
When you look at an upcoming IPO, the price band, the grey market chatter and the subscription numbers usually grab attention. Underneath all of that sits a set of rules from the Securities and Exchange Board of India (SEBI) and the stock exchanges that decides who can list, what they must disclose, and how shares are allotted and locked in. Understanding these rules will not tell you whether an IPO is worth your money, but it will help you read an offer document with a clearer eye and spot when something is unusual.
This guide walks through the framework and the recent changes retail investors should be aware of in 2026.
Who makes the rules, and why
SEBI is the statutory regulator of India's securities markets under the SEBI Act, 1992. Its stated mandate is to protect investor interests and keep markets fair and transparent. In practice, that means any company wanting to raise money from the public must file its draft prospectus with SEBI, meet eligibility norms, follow prescribed allotment procedures, and comply with post-listing obligations.
The stock exchanges, NSE and BSE, sit alongside SEBI. They run the mainboard and the SME platforms (NSE Emerge and BSE SME), set their own listing eligibility checks, and process applications and allotment. So an IPO clears two layers: SEBI's disclosure and process rules, and the exchange's listing criteria.
The core rulebook: SEBI ICDR Regulations, 2018
The central framework is the SEBI (Issue of Capital and Disclosure Requirements) Regulations, 2018, usually shortened to ICDR. These regulations standardise how securities are issued to the public, covering IPOs, follow-on offers, rights issues, qualified institutional placements and other capital raises.
The purpose is straightforward: force companies to disclose clear, detailed financial and operational information before going public, so investors are not left guessing. If you want a hands-on sense of how this shows up in practice, our explainer on what a DRHP is and how to read it breaks down the document SEBI reviews.
Eligibility: mainboard versus SME
Companies do not automatically qualify to list. The rules differ sharply by size.
Mainboard IPOs
According to the research notes, a mainboard issuer is expected to have:
- Paid-up capital of at least Rs 10 crore.
- Net tangible assets of at least Rs 3 crore in each of the three preceding years.
- Average operating profit before tax of at least Rs 15 crore in any three of the last five years (this is the profitability route).
There are alternative routes for companies that do not meet the profitability test, typically involving book-building with a higher share reserved for qualified institutional buyers. The point for you as an investor: a mainboard company has usually cleared a meaningful financial threshold.
SME IPOs
SME platform rules are lighter but still exist. Based on the research notes:
- Issue paid-up capital should not exceed Rs 25 crore.
- Net worth of at least Rs 1 crore in each of the two immediately preceding financial years.
- Operating profit (EBITDA) of at least Rs 1 crore in any two of the last three financial years, following the 2025 amendments.
- A company or promoter track record of at least three years.
SME IPOs carry different risks, lot sizes and taxation. If you are weighing one, read our comparison of mainboard versus SME IPO differences first.
How allotment is structured: investor categories and anchors
SEBI splits every book-built IPO into categories: qualified institutional buyers (QIBs), non-institutional investors (NII/HNI) and retail individual investors. Each category has a reserved portion, which is why your retail application competes only against other retail applications. Our note on QIB, NII and retail categories explains how this split works.
Anchor investor reforms
Anchor investors are large institutions that commit ahead of the public issue. Per the research notes, as of late 2025 SEBI raised the overall anchor reservation to 40% from 33%. Of that, 33% is earmarked for mutual funds and the remaining 7% for insurers and pension funds. This widens the pool of committed institutional money.
The lock-in on anchor shares is phased: the notes indicate 50% of anchor-allotted shares are locked in for 30 days from allotment, and the remaining 50% only after 90 days. The idea is to stop big institutions from dumping shares on listing day, which used to cause sharp early declines. For retail investors, a strong anchor book is often read as a signal of institutional confidence, though it is not a guarantee of listing gains.
Lock-in rules that shape post-listing supply
Lock-ins matter because they control how many shares can hit the market and when. Promoter holdings, anchor allocations and certain pre-IPO investors all face lock-in periods. When a lock-in expires, fresh supply can weigh on the price.
One technical change flagged in the research: under a March 2026 ICDR amendment, where a lock-in cannot be created in the usual way, depositories will record those securities as "non-transferable" for the lock-in duration. It is a plumbing fix, but it closes a gap. To understand why these dates matter for your timing, see IPO lock-in periods for promoters and anchor investors.
The reforms of 2025-26 you should know about
SEBI made a series of changes across 2025 and into 2026. The dates and specifics below come from the research notes and financial media rather than a single primary SEBI circular, so treat them as reported and worth verifying against the offer document you are reading.
Faster listing (T+3). SEBI has moved listing timelines to T+3 days, meaning allotment, refunds and the start of trading happen faster than the earlier T+6 cycle. For you, that means quicker refunds if you are not allotted and earlier trading if you are.
March 2025 ICDR amendments. A broad set of changes notified in March 2025, with some rights-issue provisions taking effect from April 2025.
September 2025 framework overhaul. A wider set of IPO reforms, including easier single-window access for low-risk foreign investors and relaxations aimed at absorbing very large IPOs.
Minimum public shareholding relaxation for large issuers. The notes state that companies with a post-IPO market cap above Rs 5 trillion may sell as little as 2.5% at listing (down from 5%), with extended timelines to reach the 25% public float. This is designed to let mega-listings happen without flooding the market.
Rights issue streamlining (2025). The Rs 50 crore threshold was removed, merchant banker appointment became non-mandatory for qualifying issues, and issuers now file directly with exchanges, with the process to be completed within 23 working days of board approval.
March 2026 amendments. Notified effective 21 March 2026 following SEBI's December 2025 board meeting, including the non-transferable lock-in provision above and a restructuring of abridged prospectus disclosures with QR codes and web links for easier digital access.
Promoter ESOP relaxation. Founders classified as promoters were traditionally barred from holding employee stock options; a September 2025 change relaxed this, relevant mainly for startup listings.
What this means for a retail investor
None of these rules tells you an IPO is a good investment. What they do is set the guardrails. Knowing them helps you ask better questions:
- Does this company meet mainboard financial thresholds, or is it on the SME route with lighter requirements?
- How large is the anchor book, and who are the anchors?
- When do the major lock-ins expire, and how much supply could that release?
- What did SEBI's disclosure norms force the company to reveal in the prospectus?
The rules are the floor, not a stamp of quality. Your own analysis of financials, valuation and risk still does the real work. A structured way to approach that is our 10-step framework for analysing an upcoming IPO.
FAQ
Does SEBI approve or recommend an IPO?
No. SEBI reviews the prospectus for disclosure completeness and compliance with ICDR rules. It does not vouch for the company's business, valuation or investment merit. Clearing SEBI's process is not an endorsement.
What is the T+3 listing timeline?
T+3 means shares are allotted and listed for trading within three working days of the issue closing, faster than the earlier T+6 cycle. It speeds up both refunds for non-allottees and trading for those who receive shares.
How much of an IPO is reserved for anchor investors now?
Per the research notes, SEBI raised the overall anchor reservation to 40%, with 33% earmarked for mutual funds and 7% for insurers and pension funds. This figure should be confirmed against SEBI's own circular before relying on it.
Why do lock-in expiry dates matter to me?
When promoter, anchor or pre-IPO investor lock-ins expire, those shares become sellable. If large holders exit, the added supply can pressure the price. Tracking these dates helps you understand potential post-listing volatility.
Are SME IPO rules the same as mainboard?
No. SME issuers face lower thresholds on capital, net worth and profitability, and list on separate platforms with different lot sizes and disclosure depth. SME IPOs generally carry higher risk and less liquidity.
Last reviewed: 2026-09-24. Regulatory figures and effective dates in this article are drawn from research notes and financial media; verify current thresholds against SEBI's official circulars and the specific offer document before acting.