IPO Calendar Explained

Every IPO moves through a fixed sequence of dates set out in the prospectus and enforced by SEBI timelines. Knowing what each date means, and what actually happens behind the scenes on that day, turns the IPO calendar from a list of numbers into a genuinely useful planning tool.

Why the Calendar Matters

Indian mainboard IPOs run on a standardised T+3 listing timeline, meaning the stock lists on the third working day after the issue closes. That compression is one of the reasons IPO investing feels fast-paced: from bid opening to listing is typically about a week, and every date in between has a specific function you need to plan around.

Bid Opening and Closing Dates

The issue opens for subscription on a fixed date, usually a Wednesday for mainboard issues, and stays open for three working days, though issuers can extend this in specific circumstances. During this window:

• Retail, HNI and QIB categories can bid simultaneously, though QIB demand is often concentrated on the closing day.
• Bids can be revised or cancelled by retail investors until the closing time on the final day, but not after.
• The price discovery happens through the book-building process, with investors bidding within the price band rather than at a single fixed price, except in fixed-price issues which are now uncommon at the mainboard level.

Track live subscription numbers through this window on the IPO subscription status page and see the same live premium trend on the IPO GMP list today.

Anchor Investor Date

For most mainboard IPOs, one working day before the issue opens to the public, the company allots shares to anchor investors, typically mutual funds, insurance companies and sovereign or pension funds, at a price fixed within or at the top of the band. Anchor allocations are subject to a SEBI-mandated lock-in: 50 percent of the anchor book is locked for 30 days and the remaining 50 percent for 90 days from the date of allotment. A strong anchor book, especially one dominated by long-only domestic mutual funds, is often read as a quality signal for the issue.

Basis of Allotment Date

This falls on the first working day after the issue closes. The registrar finalises how shares are allotted across categories. In an oversubscribed retail category, allotment happens through a computerised lottery rather than proportionate allocation, since the minimum lot size cannot be split further. Check your outcome as soon as it is published on the IPO allotment status page, and estimate your odds in advance using the IPO allotment calculator.

Refund and Demat Credit Dates

Refunds for unsuccessful or partially successful applicants, and demat credit for successful ones, both happen on the same working day, one day after the basis of allotment is finalised. Because most retail applications now go through ASBA and UPI mandates, "refund" typically means the blocked amount is simply unblocked in your bank account rather than a separate credit transaction; only the allotted portion is debited.

Listing Date

The stock lists on the exchange the working day after refunds and demat credit, completing the standard T+3 cycle from issue closing. Listing day itself has a specific structure:

1. A pre-open call auction runs for roughly 45 minutes before normal trading, collecting buy and sell orders to discover an equilibrium opening price without continuous matching.

2. Normal trading then begins at the discovered price, which can be well above, below, or in line with what the grey market implied.

3. Circuit filters apply on listing day, though the specific band varies by exchange and issue type.

Compare the discovered listing price against your grey market expectations by reviewing how GMP works in Indian IPOs and the limits covered in can GMP predict listing gains.

SME IPO Timelines Differ Slightly

SME IPOs, listed on the SME platforms of NSE and BSE, generally follow a similar broad structure but often have a longer minimum subscription period and different minimum application sizes. See mainboard vs SME IPOs for a full comparison of how their calendars and investor eligibility differ.

How to Actually Use the Calendar

• Mark bid opening and closing dates for every shortlisted issue and set a reminder for the UPI mandate approval well before the final cut-off time on the closing day, since mandates approved late are a common cause of rejected applications.
• Note the anchor date; a strong anchor book announced the day before opening is a useful early signal worth checking on market news.
• Plan liquidity around the blocked-funds period; ASBA locks your bid amount from application until basis of allotment, so avoid applying with funds you may need in that window.
• Use the calendar alongside the upcoming IPO list to compare multiple issues that may have overlapping windows, and use compare IPOs to weigh them side by side.

The calendar is not just a scheduling tool; each date reflects a specific regulatory and operational step in how shares move from the company's book-running lead managers to your demat account. Understanding the sequence removes a lot of the guesswork around when to act.

Frequently Asked Questions

Q: What does T+3 listing mean?

A: It means the stock lists on the exchange on the third working day after the IPO issue closes, following basis of allotment, refund and demat credit steps in between.

Q: Can I revise my bid after the issue closes?

A: No, bids can only be revised or cancelled by retail investors up to the closing time on the final bidding day, not afterward.

Q: What happens to my blocked funds if I do not get allotment?

A: Under ASBA and UPI mandates, funds are only blocked, not debited, so unallotted amounts are simply unblocked in your bank account after the basis of allotment.

Q: Is the anchor investor allotment date the same as the issue opening date?

A: No, anchor allotment typically happens one working day before the issue opens to the general public.

Q: Do SME IPOs follow the same calendar structure as mainboard IPOs?

A: They follow a broadly similar sequence but often have different minimum subscription periods and application sizes; check the specific SME issue details on the calendar.