I apologize if this has been brought up before but I had no luck searching for this topic with Google. I live in Florida and used my credit card to buy UA tickets for three family members in Chicago. They're flying down to FLL to visit us in April. On UA's web site it says,

"If you are traveling on an electronic ticket, please remember to bring a copy of your receipt with a valid photo ID and the credit card used for purchase."

Now I'm sure there must be another way to do this, other than sending them my credit card, right? Is this even necessary being that we all have the same last name? Any help would be most appreciated!

Neal