It is the responsibility of the person holding the life insurance policy to keep the beneficiary data updated as necessary. In the scenario in the question, the ex girlfriend was listed as the beneficiary ... and will be awarded the proceeds from the policy. Unfortunately, there is little the spouse can do to stop that. The beneficiary designation is binding and will hold up in a court of law.
The owner of a life insurance policy has the right to choose the beneficiary. Another person has no power to change that choice.
If an insured has a policy where there is no named beneficiary, or the named beneficiary is deceased, then the benefit will be paid to the insured's estate.
It goes to the estate
The life insurance benefit will be paid to the deceased's estate.
Benefits paid from an insurance policy are separate from property that is left in a will. With an insurance policy, it is paid to the named beneficiary. That is not controlled by the wording of a will.
the house is paid off and given to the beneficiary
The proceeds belong to the estate of the beneficiary.
Yes, you can have a secondary beneficiary on your life insurance policy. If the primary beneficiary is no longer living when you pass away, the secondary beneficiary would receive the proceeds from your life insurance policy.
The beneficiary of a life insurance policy is the person or entity designated by you when you apply for the policy and when it is issued by the insurer.
The purchaser of an insurance policy names the beneficiary.
In that case, the money will be kept deposited with the insurance company as unclaimed amount. In absence of the beneficiary, the insurance company can pay the money to the legal heir of the policy holder, but that has to be sufficiently proved in the Court of Law.
In most cases the proceeds will be paid into the estate.