The ex-date for a PSX dividend, bonus or rights issue is one settlement day before the book closure start date. That is the current rule, and it is a recent change: before February 2026 it was two settlement days, and most of what is written about PSX corporate actions still assumes the old gap.
The rule lives in the same rulebook that carried T+1 settlement into force, and it changed for the same reason — the entitlement cut-off was always defined in settlement days, so halving the settlement cycle halved the gap too. It is written into the regulation text itself, not merely implied by the shorter cycle.
What changed, and where it’s written
Two clauses carry the rule. One sets when ready-market trading flips to an ex-entitlement basis:
10.5.1(c) — “Ready Delivery Contract in a Security will be declared for settlement on T+1 settlement cycle on ex-entitlement basis at least one settlement day before the Book Closure start date of such Security…”
The other sets how the ex-price itself is computed:
10.6 DETERMINING EX-PRICE OF SECURITY ON BOOK CLOSURE — “…the Exchange shall determine the ex-price … as an opening price for the Trading Day falling one settlement day before its Books Closure start date.”
Source: PSX Regulations (Rule Book), 9 February 2026, Chapter 10, pp. 124–125.
The cleanest evidence that this is a change, not a longstanding rule, is sitting in the heading of the same clause in the previous rulebook:
10.6 DETERMINING EX-PRICE OF SECURITY ON BOOK CLOSURE – 2 SETTLEMENT DAY — “…two Settlement Day before its Books Closure start date.”
Source: PSX Rule Book, 15 February 2023.
The ”– 2 SETTLEMENT DAY” suffix was dropped from the heading, and “two” became “one”. NCCPL’s own transition circular confirms the same figure independently, in the context of corporate actions specifically:
“In case of corporate actions on a particular symbol, the ex-price shall be computed w.e.f. BC-1 in the Ready market.”
— NCCPL Circular NCCPL/CM/FEBRUARY-26/01, Transition of Settlement Cycle from T+2 to T+1, 2 February 2026, Annexure-A pt. 9.
Trading days, not calendar days
The rulebook defines T+1 by “the number of trading day after the trade day” (2.4(xcii)), and both 10.5.1(c) and 10.6 specify the gap in settlement days, not calendar days. A holiday in the window pushes the ex-date back further in calendar terms, even though the rule itself never moves.
One drafting gap worth flagging: the Regulations use “Settlement Day” throughout this clause but never formally define the term — “Trading Day” has an entry in the definitions section (2.4); “Settlement Day” does not. In practice the two have coincided in every published example we checked, but it means a sentence that leans on a precise definition of “settlement day” is standing on ground PSX hasn’t actually laid.
What buying on the ex-date does and doesn’t get you
- The buyer is on the register in time to receive the dividend, bonus or rights being declared.
- This is the session before BC-1 — the last one still trading cum-entitlement.
- Trading from BC-1 onward is declared on an ex-entitlement basis (10.5.1(c)) — the price already excludes the entitlement.
- A buyer on BC-1 or later does not receive the declared dividend, bonus or rights.
The closest a clause comes to spelling out the investor-facing consequence is written for brokers, not investors, but it points the same direction:
10.8.14 — “…delivered to the buyer at least one Settlement Day before the Book Closure start date … to enable the buyer to get the Securities transferred to his name…”
One rule, three entitlements, different arithmetic
10.5.1(c) and 10.6 both say “any entitlement” — one timing rule covers dividends, bonus shares and rights issues alike. Only the price adjustment differs:
| Entitlement | Ex-price formula |
|---|---|
| Dividend | Closing price − dividend (Rs) |
| Bonus | Closing price × 100 ÷ (bonus% + 100) |
| Rights, at par | ((Closing × 100) + (face value × right%)) ÷ (right% + 100) |
| Rights, at premium | ((Closing × 100) + ((face value + premium) × right%)) ÷ (right% + 100) |
On the issuer side, a separate rule bounds how long a book closure can run: rights and bonus book closures must start within seven working days of the corporate action, and the closure period itself “shall not be more than one (01) day” (Chapter 5.8).
The exception: stock splits
The BC-1 ex-price rule is not universal. When Bank Alfalah split its stock in April 2026, PSX issued a per-security notice overriding the normal cycle for that one trading day:
“Trading in the shares of BAFL shall be subject to a modified settlement cycle i.e. on T+0 basis (same day settlement) for the trading day BC-1 … due to stock split. However, with effect from April 20, 2026 (First Working Day after the Book Closure), normal settlement cycle i.e. T+1 shall be resumed, with adjusted price.”
— PSX Notice PSX/N-403, 10 April 2026.
For a split, the price adjustment lands after book closure, not on BC-1 — the opposite timing from a dividend, bonus or rights entitlement. PSX can and does issue notices that modify the cycle around a specific book closure, so BC-1 is the default, not a guarantee.
Why this matters more since February
Under the old T+2 cycle, the ex-date sat two sessions before book closure — enough slack that a one-day mistake in counting rarely changed the outcome. Under T+1 the gap is a single session, so miscounting by even one trading day now means buying on the wrong side of the ex-date. Anything written or memorised before February 2026 about “the last day to buy” is describing a gap that no longer exists.
The desk’s dividend and book-closure calendar is computed from the current T+1 cycle rather than a remembered rule, for exactly this reason.
Checking this yourself
- PSX Regulations, 9 February 2026 — Chapter 10, clauses 10.5.1(c) and 10.6
- PSX Rule Book, 15 February 2023 — the superseded “BC-2” text, for comparison
- NCCPL Circular NCCPL/CM/FEBRUARY-26/01 — Annexure-A, the independent BC-1 confirmation
- PSX Notice PSX/N-403 — the Bank Alfalah split, and the exception to BC-1
- PSX ex-price formulas, 5 January 2016 — the arithmetic behind each entitlement type
Version dates matter here more than usual. PSX’s own June 2026 update to its All Shares Islamic Index brochure — four months after T+1 took effect — still describes settlement “on T+2 settlement basis”, which is the same kind of stale-source trap covered in the T+1 settlement piece. If a source states a book-closure or ex-date rule without a version date on the document it’s citing, treat the number as unverified.
Research, not advice. This explains how the ex-date rule works and what the rulebook says; it is not a recommendation to buy or hold anything around a book closure. Rules are dated — check the current PSX Regulations before acting on anything time-sensitive.