What Is a Frozen ISIN? Temporary ISINs Explained

A frozen ISIN is a temporary ISIN the depositories allot to a fresh block of shares so those shares sit in demat form but cannot move. The freeze lifts only when the stock exchange grants final listing and trading permission. SEBI put the mechanism in place by circular dated 11 September 2012 and it now sits in the Master Circular for Depositories dated 3 December 2024, at para 3.2.

Why does a frozen ISIN exist at all?

Allotment and listing are two different events, and there is a gap between them. A company can allot shares under a rights issue, a preferential allotment, a bonus issue or a further public offering days or weeks before the exchange signs off on trading in those shares.

Para 3.2.2 names the problem directly: the freeze exists to curtail the transfer of such an additional issue before final listing and trading approval. Without it, allotted-but-unapproved shares could change hands in demat form while the exchange had not yet permitted them to trade.

The ISIN is the identifier the whole settlement chain keys on, so segregating the unapproved block under its own temporary identifier is what makes the restriction enforceable rather than advisory.

How the freeze is applied and lifted

Three steps, all in para 3.2:

1. Allot under a new temporary ISIN. The depositories credit the additional shares or securities into a temporary ISIN, which is kept frozen.
2. Wait for the exchange. The stock exchanges provide details to the depositories whenever final listing or trading permission is given. Where a company is listed on multiple exchanges, the exchanges must synchronise their effective dates of listing and trading approval and intimate those dates to the depositories in advance.
3. Merge into the permanent ISIN. On that approval, the balance in the temporary ISIN is debited and credited into the pre-existing ISIN for the security. Only then are the shares available for trading.

Para 3.2.5 extends the same process to units of REITs and InvITs.

When is a permanent ISIN activated in an IPO?

For an initial public offer the rule is stricter still, and it applies to the permanent ISIN rather than a temporary one.

That is the IPO analogue of the freeze. In an IPO there is no pre-existing ISIN to merge into, so the control is applied by holding activation back to the first day of trading instead.

Where the frozen status is recorded

A frozen ISIN is not something a retail investor queries directly, but it does leave a trail in the issuer-side record. The distinctive number database carries a field for the nature of the ISIN, recording whether shares were dematerialised under a temporary frozen ISIN or a permanent active ISIN, next to the allotment date, the in-principle listing date, the final trading approval date and the dealing permission date.

One small consequence worth knowing: para 3.1.3 says a temporary ISIN is not counted when computing the annual issuer charges the depositories levy. The frozen block is treated as capital in transit, not as a live folio position.

What a freeze means when you read an ownership filing

The gap between allotment and trading approval is exactly the gap where an ownership percentage can be misread. Issued capital is the denominator behind almost every ownership number, and a frozen block is issued but not tradable.

• The shareholding pattern reports promoter, FII and DII holding against total issued capital as at the quarter end, which can include an allotment whose ISIN is still frozen.
• Free float and minimum public shareholding both measure against that same issued base.
• A rights entitlement is the tradable instrument that precedes a rights allotment, and the resulting shares are the classic case of a temporary ISIN.
• Dematerialisation is the separate route by which existing physical shares enter the permanent ISIN.

Flock reports the filings themselves, each stamped with its date and linked back to the exchange or regulator that published it. What any of it means for you is your call to make.