Cook Islands law for international trusts defines an international trusts as a trust which is registered and established under the International Trust Act, whereby at least one trustees, one which may be a custodian trustee, or one of the donors who grants powers of appointment or advancement is trustee company, an international company or a registered foreign company. The beneficiaries of an international trust cannot be a resident of the Cook Islands.

In relation to determining the residency of the beneficiary of a Cook Island offshore trust, non residence, according to the Act refers to international companies, natural persons who do not live in the Cook Islands, foreign companies, trustee companies and international and foreign companies that are subsidiaries of trustee companies.

Cook Islands offshore trusts (also Belize trusts and Nevis trusts) are not affected by the rule against perpetuities or remoteness or vesting and the rule against alienability. However, a trust instrument can be written or organised in such a way that it provides for a time frame within which the trust property can be allocated to a beneficiary or the time at which such property or estate is to be handed over upon the occurrence of a particular event. Provisions may also be made through the trust instrument to not to hand over any of the trust property to one or more beneficiaries or to not have the trust terminated. In the event that the clauses of the trust are ambiguous with regard to termination, the court ruling of terminating the trust one hundred years from the date of establishing the trust will stand. Other rules which do not apply to a Cook Island offshore trust include the rule against double possibilities and the rules against accumulations which were both abolished under the International Trusts Act. The abolition of these rules however, does not prejudice or invalidate other rules of perpetuities enabled under the Act. Likewise, with reference to the rule in Saunders v Vautier under which a trustee is able to use his discretion to allow a beneficiary to request an immediate distribution of the trust property, despite provisions made regarding the rule of equity. A Cook Island offshore trust is also irrevocable unless express provisions are made for a trust to be revoked. Under the Act, detailed provisions are made for the protection of Cook Islands offshore trusts from heirship rights and spendthrift beneficiaries under the Act.

International trust instruments can be executed at anytime and anywhere outside or within the Cook Islands. Such instrument, once executed in accordance with the law is valid and can be made effected by the trustee, settlor or other party.

Besides the holding of property or estate, Cook Island offshore trusts can also be established for charity and other purposes. An offshore trust can therefore be organised to pursue good causes such as the reducing poverty, developing education and communities and disseminating religious beliefs. Someone may also choose to form an offshore trust in the Cook Islands to set up pension funds and other employee benefits.

Cook Islands offshore trusts are liable to registration fees as prescribed but are exempt from all direct taxes and duties which are imposed in the Cook Islands.