Leasehold Alternative — Sap Ing Sith

Following our previous article about the potential extension of property holding rights under the Sap Ing Sith (SIS) model from 30 to 99 years, many have asked: what exactly is this legal structure and how does it work?

What is Sap Ing Sith?

Sap Ing Sith (SIS) is a form of property right introduced in 2019 under the Sap Ing Sith Act B.E. 2562.

In essence, it is similar to leasehold, as it also provides for a limited ownership period (currently up to 30 years). However, it has several important differences that make it more attractive to investors.

What types of property can SIS be applied to?

Sap Ing Sith can be registered for:

land with a chanote title
land with a chanote title and a building
condominium units

In practice, SIS is currently most commonly used for land plots.

Important:
Unlike leasehold, SIS cannot be applied to only part of a property (for example, a portion of land).

Transfer of rights: key difference from leasehold

SIS rights are considered independent property. This means they can be:

inherited
sold
gifted
used as collateral
leased out without the owner’s consent

Leasehold:

inheritance — only if предусмотрено в договоре
sublease and assignment — only with the owner’s consent
cannot be used as collateral

Use of property

An SIS holder has broader rights:

can construct buildings on the land
can modify the property without the owner’s consent

Leasehold:

any modifications require the owner’s consent

What happens at the end of the term?

Under SIS, the property returns to the owner in its current condition — including all improvements and buildings.

If a building was constructed, the SIS holder owns it during the term of the right, after which it is transferred to the landowner.

Leasehold:

typically, the property must be returned in its original condition (unless otherwise specified in the contract)

Restrictions on the owner’s rights

When SIS is registered, the owner’s rights are limited:

cannot subdivide the land
cannot mortgage or encumber the property without the SIS holder’s consent

Leasehold:

such restrictions generally do not apply

Registration of the agreement

SIS must be registered with the Land Department regardless of the term.

Leasehold is only subject to registration if the lease term exceeds 3 years.

How common is SIS?

At present, Sap Ing Sith is used much less frequently than leasehold.

However, if the term is extended to 99 years, this model could become an effective alternative for foreign investors — especially in cases where freehold ownership is not possible.

Conclusion

Sap Ing Sith is a more flexible and secure instrument compared to leasehold, giving investors greater control over property management and use.

If legislation changes and the term is extended, it may become one of the key structures for foreign property ownership in Thailand.