Do I keep my original shares in a spin-off?

Yes. In a SOFF event the parent shares stay on the account and the shares of the separated company are credited in addition. If the original shares are exchanged, the event is an EXOF or MRGR instead.

What is the difference between SOFF and a stock dividend?

A stock dividend (DVSE) or bonus issue (BONU) credits more shares of the same company. A spin-off credits shares of another company.

How is the cost basis split after a spin-off?

The original cost is divided between the parent and the new shares, usually in proportion to their market values on a reference date set by the issuer or the tax authority. The MT564 does not always carry this; check the issuer’s tax information.

Corporate action events

SOFF: Spin-Off

Written and maintained by ZagTrader. Last reviewed 21 October 2026. How this page is sourced and checked

SOFF announces the distribution to holders of securities issued by another company, new or existing, such as in a spin-off, demerger or unbundling. Holders keep their original shares and receive the new ones in proportion. It is normally mandatory.

Code: SOFF
Usually announced as: MAND (CHOS when holders get a choice)

What SOFF means

A company may separate a business into its own listed company and hand its shares to its shareholders. SOFF is the event: each holder on the record date receives the eligible quantity times the ratio (:92a::ADEX) in shares of the other company, and keeps the parent shares.

The ECB SCoRE rulebook and the SGX guide list SOFF as MAND with SECU. A choice can occur: Clearstream, for instance, states it announces an interim liquidation that pays out securities with a choice as SOFF with CHOS.

When you see it

In an MT564 with the ex date, record date and payment date, the new ISIN in the securities movement, and how fractions are handled.
SOFF vs DVSE and BONU: those credit more shares of the same issuer; SOFF credits shares of a different company. SOFF vs EXOF or MRGR: in those the original shares are exchanged and disappear; in a spin-off they stay.
Where the distributed shares are first issued as intermediate securities, the distribution is an RHDI with :22F::RHDI//SOFF.

What to do next

No instruction for MAND. Set up the new security before the payment date, including its market and settlement details.
On the MT566, reconcile the credit of the new shares and any cash in lieu of fractions.
Split the tax cost of the parent position between the parent and the spun-off shares using the allocation the issuer or tax authority publishes, and expect index and price adjustments on the ex date.

Where it appears in MT and ISO 20022

MT (ISO 15022)

MT564 sequence A (GENL), :22F::CAEV//SOFF with :22F::CAMV//MAND (or //CHOS); sequence E1, :92a::ADEX and the new ISIN in 35B
MT566 sequence A, :22F::CAEV//SOFF

MX (ISO 20022)

seev.031 CorpActnGnlInf/EvtTp/Cd = SOFF (checked in seev.031.001.15), with the flag in CorpActnGnlInf/MndtryVlntryEvtTp/Cd
The same CorpActnGnlInf/EvtTp/Cd = SOFF appears in seev.033 (instruction) and seev.036 (movement confirmation)

Questions

Do I keep my original shares in a spin-off?: Yes. In a SOFF event the parent shares stay on the account and the shares of the separated company are credited in addition. If the original shares are exchanged, the event is an EXOF or MRGR instead.
What is the difference between SOFF and a stock dividend?: A stock dividend (DVSE) or bonus issue (BONU) credits more shares of the same company. A spin-off credits shares of another company.
How is the cost basis split after a spin-off?: The original cost is divided between the parent and the new shares, usually in proportion to their market values on a reference date set by the issuer or the tax authority. The MT564 does not always carry this; check the issuer’s tax information.