Which method requires the policy to be sent back to the insurer along with a letter for beneficiary changes?

The endorsement method is the correct choice because it specifically involves making changes to an insurance policy through an official amendment or endorsement that must be documented. This process typically requires the policyholder to return the original policy to the insurer along with a request, often in the form of a letter, specifying the desired changes to the beneficiary designation. By utilizing this method, the insurer can formally record and validate the requested changes, ensuring that all parties have a clear understanding of the updated information.

Other methods, such as the filing method, might involve maintaining records of changes without returning the original policy, while the change notice and default methods might also have different protocols that do not necessitate sending the policy back. The endorsement method stands out as the one that clearly requires the physical policy to be returned for changes to be made officially.