Members and non-members may use the cash cards to shop at any Costco location in the United States, Canada, Puerto Rico and online at Costco.com or on Costco.ca. 
Costco Cash balances may be used toward membership or merchandise. 

The Costco Cash card features include: 
A convenient payment option in our warehouses, gas stations, and costco.com
No expiration date
Are rechargeable at any Costco warehouse location
No returns and no refunds on gift cards.