How is IPO allotment decided for retail investors?

When the retail category is oversubscribed, each winning application gets the minimum lot, and the winners are picked by a computerised draw of lots among the valid applications.

Does applying for the maximum lots improve my chance?

No, not in an oversubscribed retail category. Each winner gets one lot, so the chance is the same for 1 lot or 13. More lots only block more money until the allotment.

How many days after closing is the allotment?

Under the T+3 timeline, the basis of allotment is finalised on T+1, shares are credited and money released on T+2, and the shares list on T+3, where T is the closing day.

What is the difference between small NII and big NII?

Both are applications above ₹2 lakh by non-institutional investors. Small NII goes up to ₹10 lakh and gets one third of the NII part; big NII is above ₹10 lakh and gets two thirds. In both, each winner of the draw gets the same minimum NII application, the fewest lots worth more than ₹2 lakh.

How IPO allotment works

Updated 11 October 2026

IPO allotment chance calculator →

An IPO (initial public offering) is a company selling its shares to the public for the first time, before they list on NSE and BSE. The shares are offered in a price band, in lots, for at least three working days. When a popular issue gets bids for many times the shares it has, the rules of allotment decide who gets them. Those rules are set by SEBI and are the same for every mainboard issue, which is why the arithmetic can be worked out in advance.

Who the shares are for

Every issue splits its shares into categories, and an application belongs to one of them by who applies and how much they apply for.

Retail individual investors (RII): individuals applying for up to ₹2 lakh. Most issues keep at least 35% of the shares for them.
Non-institutional investors (NII): individuals, companies and others applying for more than ₹2 lakh. Since April 2022, one third of this part is for applications up to ₹10 lakh (small NII) and two thirds for larger ones (big NII).
Qualified institutional buyers (QIB): mutual funds, insurers, banks and foreign portfolio investors. Part of their share can go to anchor investors, who are allotted shares one working day before the issue opens.

Some issues also keep a small part for their employees or for shareholders of a listed parent company. The offer document filed with SEBI gives each issue’s split, its price band and its lot size.

How you bid

You bid in whole lots through your bank or broker. The money is not taken from your account; it is blocked under ASBA (application supported by blocked amount), either through UPI, which you must use when you apply through a broker for up to ₹5 lakh, or through your bank’s net banking for any amount. A retail investor can bid at the cut-off price, which means agreeing to pay whatever issue price is fixed inside the band, and the bank blocks money at the top of the band. Retail bids can be changed or cancelled while the issue is open. NII and QIB bidders name a price and cannot withdraw or lower their bids. The IPO lot size calculator shows what each number of lots costs and which category it falls in.

The timeline: T to T+3

Since 1 December 2023, issues must list within three working days of closing. With T as the day the issue closes:

Day	What happens
T	The issue closes; the last bids and UPI approvals come in.
T+1	The basis of allotment is finalised; the result can be checked.
T+2	Shares reach the demat accounts of those allotted; blocked money is released for the rest.
T+3	The shares list and start trading on the stock exchanges.

How retail shares are shared out

If the retail category gets fewer bids than it has shares, every valid bid gets what it asked for. If it gets more, SEBI’s rules give each winning applicant the minimum lot, as many times as the shares allow, and the winners are picked by a computerised draw of lots among the valid applications. Shares left over after one lot each, if any, go in proportion to the bids for more lots.

So the number of winners is fixed in advance: the shares in the retail category ÷ the lot size. The chance for one application is that number ÷ the valid applications.

Worked example

Company ABC’s IPO keeps 35,00,000 shares for retail investors, in lots of 50 shares. That is 70,000 lots, so up to 70,000 retail applicants can get shares. The retail category is subscribed 40 times: bids for 14,00,00,000 shares, or 28,00,000 lots. The basis of allotment shows 7,00,000 valid retail applications, which asked for 4 lots each on average.

Chance for one application: 70,000 ÷ 7,00,000 = 10%, or 1 in 10.
If all 28,00,000 lots had been asked for one per application, the chance would have been 70,000 ÷ 28,00,000 = 2.5%, or 1 in 40. That is the lowest the chance can be at 40 times.
In general, the chance is the average lots per application ÷ the times subscribed: 4 ÷ 40 = 10%.

The IPO allotment chance calculator does this for any issue, from the number of applications or from the times subscribed.

Why more lots do not help, and what does

Every winning retail application gets one lot, so an application for 13 lots has the same chance as one for 1 lot. The bigger application only blocks more money until T+2. The chance rises only with more applications, and each needs its own PAN and demat account: two applications under the same PAN count as multiple applications, and all of them can be rejected. With three applications from three family members, each with a 10% chance, the chance that at least one gets a lot is 1 − 0.9 × 0.9 × 0.9 = 27.1%. Each of the three still blocks its own amount.

Small and big NII

Since April 2022 the NII categories follow the same idea. Each winner in small NII and in big NII gets the minimum NII application, the fewest lots worth more than ₹2 lakh, even though a big NII application is above ₹10 lakh. When there are more applicants than such blocks, a draw of lots picks the winners, and a bigger NII application does not raise the chance of getting one. Only when there are enough blocks for everyone do the leftover shares go out in proportion to the size of each application.

Checking the result

From T+1, the registrar named in the offer document shows the allotment status on its website when you enter your PAN or application number, and BSE and NSE have their own status pages. If you got shares, they appear in your demat account on T+2. If not, the blocked amount is released the same day. The IPO calendar lists the mainboard issues open now, each with its registrar.

What allotment does not tell you

Getting shares says nothing about the listing price, which is found in a special pre-open session on the listing day and can be below the issue price. Figures that circulate before listing, such as the grey market premium, come from informal deals outside the stock exchanges that no regulator oversees; this site does not show or use them. If you sell, the IPO listing gain calculator works out the charges and the tax on any price you type.

Questions people ask

How is IPO allotment decided for retail investors?: When the retail category is oversubscribed, each winning application gets the minimum lot, and the winners are picked by a computerised draw of lots among the valid applications.
Does applying for the maximum lots improve my chance?: No, not in an oversubscribed retail category. Each winner gets one lot, so the chance is the same for 1 lot or 13. More lots only block more money until the allotment.
How many days after closing is the allotment?: Under the T+3 timeline, the basis of allotment is finalised on T+1, shares are credited and money released on T+2, and the shares list on T+3, where T is the closing day.
What is the difference between small NII and big NII?: Both are applications above ₹2 lakh by non-institutional investors. Small NII goes up to ₹10 lakh and gets one third of the NII part; big NII is above ₹10 lakh and gets two thirds. In both, each winner of the draw gets the same minimum NII application, the fewest lots worth more than ₹2 lakh.