A Mainboard IPO lists large, established companies directly on the NSE or BSE main exchange and requires a post-issue paid-up capital of at least ₹10 crore along with SEBI-defined profitability, net worth, and asset criteria. An SME IPO lets smaller businesses list on the NSE Emerge or BSE SME platform, with post-issue paid-up capital capped at ₹25 crore, lighter disclosure norms, and oversight by the stock exchange rather than direct SEBI vetting. The core trade-off is company scale and regulatory rigour on one side versus accessibility and growth capital for smaller firms on the other.
India's IPO market has matured into two distinct tracks. Large, established companies raise capital through a Mainboard IPO and list directly on the NSE or BSE. Smaller, high-growth businesses — the kind that form the backbone of the Indian economy — use the SME IPO route to list on the NSE Emerge or BSE SME platform instead. Both routes are governed by the Securities and Exchange Board of India (SEBI) under the SEBI (Issue of Capital and Disclosure Requirements) Regulations, 2018 (“SEBI ICDR Regulations”), but the eligibility bar, oversight process, investment size, and risk profile differ sharply between the two. This guide breaks down exactly how, so you can read an IPO prospectus and know which category you're looking at — and what that means for you as an investor.
What Is a Mainboard IPO?
A Mainboard IPO is the process by which an established private company sells shares to the public for the first time and lists directly on the main board of the NSE or BSE, subject to SEBI's full ICDR eligibility, disclosure, and profitability norms.
When a company goes public through the Mainboard route, its shares begin trading on the primary segment of India's leading exchanges alongside long-listed large-caps and mid-caps. Because these companies are typically larger and more financially established, SEBI subjects them to the strictest disclosure and eligibility framework in Indian capital markets.
Mainboard IPO Eligibility — SEBI ICDR Regulations, 2018
SEBI allows a company to qualify for a Mainboard IPO through one of two routes:
|
Route |
Who It's For |
Key Requirements |
|
Profitability Route (Entry Norm I) |
Established, profitable companies |
Net tangible assets ≥ ₹3 crore in each of the preceding 3 years; average operating (pre-tax) profit ≥ ₹15 crore in at least 3 of the preceding 5 years; net worth ≥ ₹1 crore in each of the preceding 3 years; post-issue paid-up capital ≥ ₹10 crore. |
|
QIB Route (Entry Norm II) |
High-growth, not-yet-profitable companies (e.g., new-age tech businesses) |
Issue made through the book-building process with at least 75% of the net offer allocated to Qualified Institutional Buyers (QIBs); if minimum QIB subscription isn't met, the entire issue is refunded. Recent large tech listings have used this route. |
On top of SEBI's baseline norms, the exchanges (NSE and BSE) apply their own additional listing conditions — including a clean litigation and insolvency record, at least three years of audited financial statements, and no pending disciplinary action against promoters or directors by SEBI. The DRHP (Draft Red Herring Prospectus) for a Mainboard IPO is filed with and directly examined by SEBI, which can raise queries or delay the issue until it is satisfied.
Pros and Cons of a Mainboard IPO
|
Pros |
Cons |
|
Access to a much larger pool of public and institutional capital |
High cost of the IPO process and ongoing listing compliance |
|
Improved brand visibility, credibility, and access to cheaper credit |
Mandatory disclosure of financial and strategic information, including to competitors |
|
Deep liquidity — shares can be bought or sold in any quantity, including single shares, once listed |
Quarterly reporting and continuous regulatory scrutiny add long-term compliance overhead |
|
SEBI's direct vetting of the DRHP adds a layer of regulatory assurance for investors |
Longer, more document-intensive approval timeline compared to an SME IPO |
What Is an SME IPO?
Definition
An SME IPO is the process by which a small or medium enterprise raises capital by listing on a dedicated SME platform — NSE Emerge or BSE SME — under SEBI ICDR Chapter IX (Regulation 229), subject to a lighter disclosure regime and exchange-level (rather than direct SEBI) vetting.
SMEs are widely regarded as the backbone of the Indian economy, but they have historically struggled to access institutional funding and public capital markets on Mainboard-scale terms. The SME IPO framework, introduced in 2012, gives smaller companies a dedicated listing route with simpler, faster, and comparatively lower-cost compliance.
SME IPO Eligibility — SEBI ICDR Regulations, 2018 (Chapter IX)
• Post-issue paid-up capital must not exceed ₹25 crore — companies that cross this ceiling must list on the Mainboard instead.
• A minimum operational track record, generally at least 3 years, is required.
• Following SEBI's March 2025 tightening, an issuer must show an operating profit (EBITDA) of at least ₹1 crore in at least 2 of the preceding 3 financial years; issuers unable to meet this must instead satisfy a defined net worth threshold.
• A SEBI-registered merchant banker must handle underwriting, with underwriters committing to at least 15% of the issue size — mandatory underwriting is a distinguishing feature versus Mainboard IPOs.
• The offer document is filed with, examined, and approved by the designated stock exchange (BSE SME or NSE Emerge) rather than SEBI directly — SEBI's role here is supervisory, which is why SME prospectuses carry a standard disclaimer noting SEBI has not vetted the offer.
SEBI's March 2025 SME IPO Reforms
After a wave of SME listings through 2023–24, SEBI identified a recurring pattern of concern: some issuers were diverting IPO proceeds to related parties, inflating revenues through circular transactions between group entities, and in at least one publicly reported case, had an SME IPO cancelled outright after evidence of fund misuse. In response, SEBI tightened the SME framework in March 2025:
• Minimum SME IPO application size raised from ₹1 lakh to ₹2 lakh — directly raising the entry cost for retail investors.
• A firmer profitability requirement (EBITDA ≥ ₹1 crore in 2 of the last 3 years), replacing looser revenue-growth-only tests.
• Promoter selling is now capped — generally no more than 20% of the total issue size, and no more than 50% of a promoter's overall holding, via Offer for Sale (OFS).
• IPO proceeds can no longer be used to repay loans owed to promoters or related parties.
• NSE Emerge has separately capped Day-1 listing price movement at 90% above the issue price, to curb speculative opening-day spikes.
Pros and Cons of an SME IPO
|
Pros |
Cons |
|
Simpler, faster, lower-cost route to public capital for smaller companies |
Higher business risk — SMEs list very early in their growth lifecycle, with thinner track records |
|
Connects listed businesses with long-term institutional investors |
Minimum application size of ₹2 lakh (post-March 2025) is a high entry barrier for small retail investors |
|
A track record on the SME platform can support migration to the Mainboard as the company scales |
Offer document is vetted by the exchange, not SEBI directly — a materially lighter scrutiny layer |
|
Lower listing and compliance costs than a Mainboard IPO |
Lower analyst coverage and liquidity compared to Mainboard-listed stocks |
Mainboard IPO vs SME IPO: Side-by-Side Comparison
|
Parameter |
Mainboard IPO |
SME IPO |
|
Listing Platform |
NSE / BSE main board |
NSE Emerge / BSE SME |
|
Post-Issue Paid-Up Capital |
≥ ₹10 crore |
Up to ₹25 crore (ceiling, not minimum) |
|
Regulator Vetting DRHP/Offer Document |
SEBI directly reviews and can raise queries |
Designated stock exchange vets the offer document; SEBI's role is supervisory |
|
Profitability Requirement |
Avg. operating profit ≥ ₹15 cr (3 of last 5 yrs) under Entry Norm I, or QIB Route for loss-making issuers |
EBITDA ≥ ₹1 cr in 2 of last 3 years (post-March 2025 norms) |
|
Minimum Application Size |
Typically ₹14,000–₹15,000 per lot |
₹2 lakh minimum (raised from ₹1 lakh in March 2025) |
|
Underwriting |
Not mandatory in all cases |
Mandatory — underwriters commit to ≥ 15% of issue |
|
Liquidity After Listing |
High — trade in any quantity, deep institutional participation |
Comparatively lower; thinner analyst and institutional coverage |
|
Typical Issuer Profile |
Large, established companies with a multi-year track record |
Small and medium enterprises early in their public-market journey |
Conclusion
Both Mainboard and SME IPOs give Indian companies a route to public capital — the difference is scale, oversight, and risk. A Mainboard IPO suits large, established businesses that can meet SEBI's stricter profitability and disclosure bar and offers investors deeper liquidity and direct SEBI vetting. An SME IPO opens the public markets to smaller, earlier-stage businesses, but with a lighter regulatory net, thinner liquidity, and — since March 2025 — a meaningfully higher entry ticket for retail investors. Subscription demand or a strong grey market premium is not, on its own, a reason to apply; eligibility route, use of issue proceeds, and who actually reviewed the offer document matter more to your risk than headline oversubscription numbers.
DISCLAIMER: This blog is NOT any buy or sell recommendation. No investment or trading advice is given. The content is purely for educational and information purposes only. Always consult your eligible financial advisor for investment-related decisions.
