SME IPO vs mainboard IPO: key differences explained

Updated 26 October 2026 · 6 min read

Indian IPOs come in two kinds. Mainboard IPOs list on the main segment of NSE and BSE, where most well-known companies trade. SME IPOs list on separate platforms meant for small and medium enterprises: NSE Emerge and BSE SME. On a broker app the two look almost identical — a price band, a lot size, three days to bid — but the rules behind them, the money you need and the risks you take are quite different.

In short: SME IPOs are smaller companies, raise less money, need a much larger minimum application, are reviewed by the stock exchange rather than SEBI, and trade with far less liquidity after listing. This guide goes through each difference and what it means for you as an investor.

Where they list and who reviews the documents

A mainboard company files its draft red herring prospectus (DRHP) with SEBI, which reviews it and issues observations before the IPO can go ahead. An SME company files its draft offer document with the SME platform of the exchange, which does the review. Disclosure requirements are broadly similar in structure but lighter in places, and the level of outside scrutiny is lower. That puts more of the checking work on you.

Both kinds of issue must appoint a merchant banker (lead manager) and a registrar, both use ASBA and UPI for applications, and both follow the T+3 listing timeline. The application process in your broker app is the same.

Size of the company and the issue

Mainboard IPOs typically raise from a few hundred crores to several thousand crores, from companies with a long operating history. SME IPOs usually raise a few crores to a few tens of crores, from companies with smaller revenues and often a short public track record. A small issue size means a few large investors can dominate the book, and a small free float after listing means a few trades can move the price sharply.

Minimum application: two lots since 2025

Mainboard lot sizes are set so that one lot costs roughly ₹10,000–15,000, which keeps IPOs open to small investors. SME lots have always been larger, and since 2025 the rules require a minimum application of two lots, with the application value above ₹2 lakh. In practice that makes every SME application an HNI-sized ticket.

Say an SME IPO is priced at ₹120 with a lot of 1,000 shares. One lot is ₹1.2 lakh, so the minimum application of two lots is ₹2.4 lakh. If you are allotted, all ₹2.4 lakh is in a single small company — a far bigger bet than one mainboard lot.

The 2025 changes also added profitability requirements for SME issuers and limits on how much of an issue can be an offer for sale by existing shareholders, and on how the money raised can be used. The exact conditions are set by SEBI and the exchanges and can change, so check the RHP of each issue.

Market making and liquidity

Every SME IPO must appoint a market maker, who is obliged to quote buy and sell prices for the stock for three years after listing. This exists because SME shares would otherwise trade very rarely. Market making helps, but it does not guarantee you can sell a large quantity at a fair price: quotes can be wide apart, and on a falling day buyers can be scarce.

• SME shares trade in lots, not single shares, so you can buy or sell only in multiples of the trading lot.
• Daily volumes are often thin; a few lots can be the whole day's trade.
• Mainboard shares can be bought and sold one share at a time, with much deeper order books.

Listing day differences

Both mainboard and SME IPOs list through a special pre-open session from 9:00 to 10:00 am, where the listing price is discovered from orders placed, and normal trading starts at 10:00 am. A price band applies on listing day for both, but the band for SME listings is tighter. After a period of very large SME listing gains, the exchanges also added extra checks on SME listings. The details change, so keep expectations general: an SME stock can be locked at its band within minutes on listing day, in either direction.

Side-by-side comparison

Migration from SME platform to main board

An SME company does not have to stay on the SME platform forever. Once it grows and meets the exchange's migration criteria — usually a minimum time listed on the SME platform plus thresholds for size, profitability and shareholder numbers — it can apply to move to the main board. Shareholder approval is also needed. Migration can improve liquidity and visibility, but it is not automatic and not guaranteed; plenty of SME companies stay on the platform for years. Do not buy an SME IPO on the assumption that it will migrate.

Which should a first-time investor look at?

This is not a recommendation either way, but the structure answers part of the question. Mainboard IPOs let you start with one small lot, are reviewed by SEBI and are easy to sell. SME IPOs need above ₹2 lakh per application, carry company-specific risks that are harder to judge, and can be hard to exit. Many investors build some experience with mainboard issues and the RHP before considering SME issues at all. Our separate guide on SME IPO risks explains what to check.

On IPOScanner, SME issues carry an "SME" tag. Each IPO page shows the price band, lot size, minimum application, live subscription by category and the GMP trend, and "＋ I applied" adds the issue to My IPOs to follow allotment and listing.