Which type of beneficiary cannot be changed without written consent?

An irrevocable beneficiary is one whose designation cannot be changed without their written consent. This type of beneficiary has a vested interest in the policy and thus has certain rights that protect their interests. Once a beneficiary is designated as irrevocable, the policyholder cannot alter this designation, take out loans against the policy, or make changes to the policy that would affect the irrevocable beneficiary's interest without obtaining their approval. This structure is often used to provide assurance to a beneficiary, such as in estate planning, where a certain party is guaranteed benefits and cannot be easily removed by the policyholder.

In contrast, a primary beneficiary can generally be changed at any time by the policyholder without needing the primary beneficiary's consent. Similarly, contingent beneficiaries and revocable beneficiaries can also be changed freely by the policyholder, indicating that they do not have the same level of rights and protections as an irrevocable beneficiary.