You can purchase additional Business Membership cards at any time during the renewal year. The annual cost is $60 per card (the additional Business Membership card plus one Household Member card, which can be assigned to anyone over 16 at the same address).

There are four ways to add a Business Membership card:

1. Head to Costco.com and sign in to access your account details. Once your membership has been verified, select the Business Details section to manage your additional cardholders.
2. Visit the membership counter at any Costco warehouse. You’ll find locations and phone numbers for all of our Costco locations right here.
3. Give Member Services a call at 1-800-774-2678.
4. Fax your request to 425-313-6870 (Attn: Member Services) on company letterhead.
   
   If you’re faxing a letter, be sure to include the names, addresses, and phone numbers for anyone you’re adding, along with the signature of the Primary Member or Business Account Manager for authorization. Please also list a contact name and phone number—a representative will call to obtain a credit card number to charge any applicable fees.