Many Costco members wonder whether they can legally add a third person to an existing membership. Understanding the official household rules and the steps for adding authorized cardholders helps you avoid confusion at the register.
The short answer is yes, you can add a third person, but this individual must qualify as an authorized cardholder linked to your primary household account. The following sections outline eligibility, methods, responsibilities, and common questions in detail.
| Aspect | Details | Impact if Not Followed | Best Practice |
|---|---|---|---|
| Who can be added | Authorized cardholders must live in the same primary household | Account review or removal of privileges | Confirm shared living address before adding |
| Number allowed | Costco generally allows up to two authorized cardholders per membership | Exceeding limit may require plan change or new membership | Check current plan tier and household limit |
| Documentation needed | Proof of address and identification for new cardholder | Delay in activation if documents are missing | Have digital or printed copies ready |
| Fees | No extra fee for authorized cardholders in most cases, but higher tiers may have more cardholders included | Unexpected charges if plan specifics differ | Review membership plan benefits online |
Understanding Household Eligibility
Costco defines a household as people who live at the same permanent address and share regular meals. When you add a third person, that individual must meet this household definition to qualify as an authorized cardholder.
If the third person does not reside with you full time or does not share meal patterns, they may not be added under your current membership. The membership remains primarily responsible to the primary account holder for all charges and compliance.
How to Add a Third Person as Authorized Cardholder
You can usually add a third person by visiting a Costco warehouse, calling member services, or using the online account portal where allowed. Each method requires verifying the new cardholder’s identity and residential address.
Bring documents such as a driver’s license or utility bill to prove eligibility. Once approved, the new cardholder receives their membership number and a separate card with a unique number linked to your account.
Responsibilities and Limitations
The primary account holder is financially and administratively responsible for all authorized cardholders, including the third person. This includes any purchases, violations, or required membership renewals.
Authorized cardholders must follow the same rules as the primary member, including item restrictions and membership terms. The household limit on cardholders, often two authorized users, should be verified with Costco directly to confirm current policy.
Plan Differences and Membership Tiers
Your membership plan can affect how many cardholders you may add and what benefits each receives. Higher membership tiers sometimes include more included cardholders or additional services for larger households.
Before adding a third person, review your plan details online or at the warehouse to ensure you remain within allowed limits and understand any potential changes in fees or access.
Key Takeaways for Adding a Third Cardholder
- Only add individuals who live in your primary household and share meals.
- Verify your membership plan’s included cardholder count and any fees.
- Prepare identification and proof of address before requesting the addition.
- The primary member remains responsible for all authorized cardholder activity.
- Review Costco policies periodically as rules and plans may change over time.
FAQ
Reader questions
Can I add a friend who does not live with me as a cardholder?
No, Costco requires authorized cardholders to reside in the same primary household, so a friend who does not share your address cannot be added.
What documents do I need to add a third person to my membership?
Prepare proof of address and a government-issued photo ID for the new cardholder, such as a driver’s license or state ID card.
Will adding a third person cost extra fees?
Typically there is no fee for authorized cardholders, but certain membership plans or regions may have variations, so verify your specific plan benefits.
Who is responsible if the third person misuses the card?
The primary account holder is responsible for all purchases and compliance by authorized cardholders, including the third person added to the membership.