Reviewed on 24 Oct 2026 · Source: IPO Bulletin explainer; checked against SEBI ICDR Regulations 2018 (as amended) and offer-document practice
The allotment" data-term="basis-of-allotment" aria-describedby="ipob-def-basis-of-allotment">basis of allotment is the method and result by which shares are distributed among applicants after an IPO closes. It is finalised by the registrar to the issue in consultation with the stock exchange, and the exchange approves it before shares are credited. The document lists, for each category, how many applications were received, how many shares were applied for, the oversubscription ratio, and how many applicants received how many lots. Where a category is undersubscribed, every valid applicant gets the full quantity applied for. Where it is oversubscribed, shares are allotted proportionately in the QIB and NII categories, and by a computerised lottery in the retail category, so the minimum allotment is one lot. Because the basis shows exactly how many lots each applicant got, it is the best proof of how fair the process was. The basis of allotment is usually published on the registrar’s website and the exchanges one working day after the issue closes, around the T plus 1 day. Investors can then check their status using their application number or PAN.
Example: A retail category has 20,000 lots to give and receives 200,000 valid applications. The basis of allotment would record that 1 out of every 10 applicants gets 1 lot, selected by lottery, and the other 9 get none.
The registrar to the issue, often just called the IPO registrar, is the SEBI-registered agency that handles the administrative backbone of an IPO after the bidding closes. It collects and validates the applications received from the exchanges and banks, matches PAN and demat details, removes duplicates and invalid bids, prepares the basis of allotment with the exchange, instructs the depositories to credit shares, arranges unblocking of money through banks, and handles investor queries and complaints about allotment and refunds. Well-known registrars include KFin Technologies, MUFG Intime India, Bigshare Services and Link Intime, among others, and their websites provide an allotment status page where you can check whether you received shares using your PAN, application number or DP ID. After listing, the same agency often continues as the company's share transfer agent. The registrar's name and contact details are printed in the offer documents and on IPO Bulletin's IPO pages. If your allotment status does not match your bank statement or demat account, contact the registrar first, then the lead manager and your bank, and if still unresolved, lodge a complaint on SEBI's SCORES platform.
The basis of allotment is the method and result by which shares are distributed among applicants after an IPO closes. It is finalised by the registrar to the issue in consultation with the stock exchange, and the exchange approves it before shares are credited. The document lists, for each category, how many applications were received, how many shares were applied for, the oversubscription ratio, and how many applicants received how many lots. Where a category is undersubscribed, every valid applicant gets the full quantity applied for. Where it is oversubscribed, shares are allotted proportionately in the QIB and NII categories, and by a computerised lottery in the retail category, so the minimum allotment is one lot. Because the basis shows exactly how many lots each applicant got, it is the best proof of how fair the process was. The basis of allotment is usually published on the registrar's website and the exchanges one working day after the issue closes, around the T plus 1 day. Investors can then check their status using their application number or PAN.
Oversubscription happens when investors apply for more shares in an IPO than the company is offering. If a category is subscribed 5 times, applicants asked for five shares for each one available. When this occurs, not everyone can receive what they asked for, so allotment follows rules set by SEBI. In the retail category, a computerised lottery picks applicants who each get the minimum lot, which means many applicants receive nothing. In the QIB and NII categories, shares are allotted proportionately, so each bidder gets a smaller share of what it applied for, subject to minimum lot rules. Heavy oversubscription is read as a sign of strong interest, and it often lowers the retail allotment odds. A company can retain the oversubscription only up to the limits in the offer document; the greenshoe option, available in some issues, allows a stabilising agent to handle part of the excess demand after listing. Investors should remember that many bids are placed with borrowed money and are cancelled or reduced after allotment, so high figures do not always mean sustained demand. The reverse, undersubscription, means the issue is not fully taken up, and the company may fail to raise the minimum amount.
Allotment is the step after an IPO closes in which the company decides who receives shares and how many. Once bidding ends, the registrar prepares the basis of allotment, which explains how the shares were shared between categories and applicants. If an issue is not oversubscribed in a category, most valid applicants get what they asked for. If it is oversubscribed, shares are rationed. In the retail category, successful applicants are chosen by a computerised lottery and each winner usually receives one lot, because the demand is far larger than the supply. Larger categories receive shares in proportion to their bids. After allotment, shares are credited to the demat accounts of successful applicants, and money for unsuccessful applications is released from the ASBA block. SEBI requires the whole process, from issue close to listing, to be completed within three working days. You can check your allotment status on the registrar's website using your application number, PAN or demat details, and on the exchange page for the issue.
Worked example
A retail category has 20,000 lots to give and receives 200,000 valid applications. The basis of allotment would record that 1 out of every 10 applicants gets 1 lot, selected by lottery, and the other 9 get none.
