Proof is unnecessary.
If you do not live with an unrelated person of the opposite sex and you say that you are not married, we will generally accept your statement unless we have information to the contrary. If you are under age 22 and have been married, to prove that your marriage has ended you must show us the decree of divorce or annulment or the death certificate if you can. If you cannot, you must tell us why not and give us whatever evidence you can.