# How to read the basis of allotment

Source page: https://ipo24by7.com/learn/basis-of-allotment/ · Updated 2026-11-03 · By IPO24by7 Research

The basis of allotment of an IPO is the official record of how shares were given out in each investor category. It is finalised by the registrar with the stock exchange on T+1, and published as a notice and newspaper advertisement. Its ratio column, such as 1 in 43, shows the real odds in your category.

## Key takeaways

- The basis of allotment is finalised on T+1 by the registrar with the designated stock exchange.
- It is published in newspapers and filed with the exchanges, usually within a day or two.
- The ratio column, such as 1 in 43, shows the share of valid applicants who got shares.
- It counts valid applications only; rejected bids are left out.
- It confirms the final issue price and the anchor and category split used.

## What the basis of allotment is

When bidding closes, the registrar collects every application, removes invalid ones, and works out how many shares each valid applicant gets under SEBI's rules. The **designated stock exchange** checks and approves this. The result is the **basis of allotment**.

Under the T+3 timeline, it must be finalised by 6 pm on T+1, the working day after the issue closes. Allotment status goes live that evening.

## Where to find it

- **Exchange announcements.** The company files it with NSE and BSE.
- **Newspapers.** An advertisement with the basis of allotment appears in national and regional papers.
- **The registrar's website.** Some registrars post it alongside the allotment status page.

Each IPO page on IPO24by7 names the registrar. The [allotment status page](/ipo/allotment-status/) links to each one.

## What is in it

A basis of allotment notice usually has these parts:

1. **The final issue price**, and any discount for retail or employees.
2. **The subscription** by category, after removing invalid bids.
3. **The anchor allocation**, already done before the issue opened.
4. **One table per category** (retail, small NII, big NII, QIB, employee, shareholder), showing how shares were allotted at each bid size.
5. **Confirmation of dates** for refunds, demat credit and listing.

## Reading a category table

Each category table lists every bid size, from one lot upwards. For each row it typically shows:

| Column | What it tells you |
|---|---|
| Category (bid size) | How many shares were applied for, such as 100, 200, 300 |
| Number of applications | Valid applications at that size |
| Total shares applied | Applications × bid size |
| Ratio of allottees to applicants | For example, 1 : 43, meaning one in 43 got shares |
| Shares allotted per allottee | Usually one minimum lot in an oversubscribed retail category |
| Total shares allotted | What that row received in all |

In an oversubscribed retail category, the ratio is usually the same in every row. That is how you can see that bidding for more lots did not help.

## A worked example

BLS Polymers closed on 29 October 2026 with retail subscribed 128.36 times, according to NSE's bid details. Its price was ₹142 to ₹150 with a lot of 100 shares, and retail was 35% of the issue.

At the cap, 35% of its 1.70 crore new shares is about 59,50,000 shares, or 59,500 lots, for retail (our calculation). At 128.36 times, retail bids were about 76.4 crore shares. Here is how the retail table could look if 25,58,500 valid applications came in. The application counts are illustrative, not from the actual notice.

| Bid size (shares) | Applications | Ratio | Shares allotted |
|---|---|---|---|
| 100 | 18,88,500 | 1 : 43 | 43,91,900 |
| 500 | 3,70,000 | 1 : 43 | 8,60,500 |
| 1,300 | 3,00,000 | 1 : 43 | 6,97,700 |

Each winner in every row gets 100 shares, one lot.

Every row has the same ratio, and the shares allotted add up to the 59,500 lots available. An applicant for 13 lots had the same one-in-43 chance as an applicant for one lot, and the winner got the same single lot. These numbers are our illustration.

## How a ratio is worked out

1. **Lots available:** the shares in the category divided by the lot size.
2. **Valid applications:** from the registrar's count.
3. **Ratio:** applications divided by lots. If 25,58,500 applications compete for 59,500 lots, the ratio is 1 in 43.

The lottery itself is computerised and supervised by the designated stock exchange. Read [chances of getting an IPO allotment](/learn/chances-of-ipo-allotment/) for what affects your odds.

## Using it for the next IPO

The basis of allotment is the best record of how competitive each category really was. Over a few issues, it shows a pattern: how many valid retail applications a popular mainboard IPO draws, and how the small NII odds compare with retail.

That helps set expectations. It does not predict the next issue, because demand depends on the company, the size of the issue and the market that week. Keep in mind too that subscription during bidding counts shares, while the notice counts people. A category subscribed 100 times can still give a one-in-30 chance if most applicants bid for several lots, or a one-in-90 chance if most bid for one.

## Other things the notice shows

- **Rejected applications.** Some notices give the number rejected and the reasons, such as PAN mismatch or duplicate bids.
- **Spill-over.** If a category was undersubscribed, the notice shows how the unsubscribed shares were moved to other categories.
- **The final price.** Confirms whether the price was set at the cap or lower.
- **The anchor list.** Some notices repeat the anchor allocation, with the investors' names and the shares each received before the issue opened.
- **Employee and shareholder quotas.** Where offered, each has its own table, often with a better ratio than retail.

## When the ratio is not the whole story

In a lightly subscribed category, the table looks different. Every applicant gets at least the minimum lot, and the shares left over are shared out in proportion to the bids. Larger bids then do get more shares, and the "shares each" column rises with the bid size.

The NII tables follow their own rules. Small NII and big NII winners are first chosen by lottery for the minimum application size in their pool. If shares remain, they are allotted in proportion to the bids. So the NII tables often show both a ratio and a larger allotment for bigger bids.

## What the final price means for your money

The notice confirms the final issue price. If it was set below the cap, everyone who bid at cut-off or above paid the lower price. The difference between the cap and the final price, for the shares allotted, was released with the rest of the blocked money on T+2. Read [what happens to your money if you are not allotted](/learn/ipo-not-allotted-refund/).

## Basis of allotment in SME IPOs

The same notice is published for SME IPOs. The individual investor table works the same way, except the minimum application is two lots, worth more than ₹2 lakh. Each winner gets that minimum, chosen by lottery.

SME notices also show the shares allotted to the market maker, separately from the investor categories.

## Common mistakes to avoid

- **Looking for your name in the notice.** It shows totals; check your own status on the registrar's site.
- **Reading the ratio as your fixed odds next time.** Every IPO's ratio depends on its own demand.
- **Comparing with subscription figures directly.** The notice counts valid bids only.
- **Missing the final price.** If the price was set below the cap, the difference was released to you.

## What to do next

Learn [how IPO shares are allotted](/learn/ipo-allotment-process/) and [how to check your allotment status](/learn/how-to-check-ipo-allotment-status/). Then see the dates for every open IPO on the [allotment status page](/ipo/allotment-status/).

## Frequently asked questions

**What is the basis of allotment in an IPO?**
It is the method and result of allotting shares in each investor category, approved by the designated stock exchange. It shows how many valid applications there were, how many got shares and how many shares each received.

**When is the basis of allotment published?**
It is finalised on T+1, the working day after the issue closes. The registrar and company publish it as an announcement to the exchanges and an advertisement in newspapers, usually by the next day or two.

**Where can I find the basis of allotment?**
In the company's announcement on NSE and BSE, on the registrar's website, and in newspaper advertisements. Each IPO page on IPO24by7 links to the registrar.

**What does 1 in 43 mean in the basis of allotment?**
It means about one of every 43 valid applicants in that bid size got the minimum lot, chosen by lottery. The other 42 got nothing.

**Does the basis of allotment show my own result?**
No. It shows totals by category and bid size. Check your own result with your PAN or application number on the registrar's site, or on BSE or NSE.

**Why does the number of applications differ from the subscription data?**
The subscription figures during bidding include bids that are later found invalid. The basis of allotment counts only valid applications, so its totals are usually a little lower.

## Sources

- SEBI (Issue of Capital and Disclosure Requirements) Regulations, 2018, Schedule XIV: allotment procedure and basis of allotment by category
- SEBI circular SEBI/HO/CFD/TPD1/CIR/P/2023/140, 9 Aug 2023 (T+3): basis of allotment to be finalised by 6 pm on T+1
- BLS Polymers RHP and NSE bid details, 29 Oct 2026, for the worked example (application counts illustrative)

Information only, not investment advice.