This has come up several times. Although it is true that it is not legal to sell alcohol or tobacco to an underage person, so far, nobody has been able to provide a citation to a statute in Oklahoma that requires a buyer to show ID to complete the purchase. The merchant can require the buyer to show ID (and they’re wise to do so in most conditions), but that’s just a store policy, not a law.There are laws that make it mandatory to show ID when making those purchases.