To shop at Costco, you need a membership, but members can bring along up to two guests at a time. However, guests cannot pay at checkout, as only members have the ability to pay.

This rule can be circumvented. Costco members can add an additional free household card, so if you live with a member, they can put you on their plan.

Non-members can also receive a Costco Shop Card to shop at the chain as they please. Only members can purchase this rechargeable card and gift it to a non-member.