Costco's policy lets you return half-eaten food, but they won't take back these eight items

Costco has a famously generous returns policy that offers its loyal customers a '100 percent satisfaction guarantee.'

According to its website, Costco does not specify any expiration date on refunds nor does it state that a customer needs to bring their receipt.

Customers have tested the bounds of the generous policy by returning two-year-old vacuums and couches.  

The warehouse-based chain will even let customers return half-eaten food if there is a problem with the product or it goes bad before the sell-by date.  

However, there are eight key items that Costco - which last week raised its membership prices for the first time in seven years - does not allow returns for. 

1. Electronics purchased more than 90 days ago

Although some electronic items, such as vacuums, qualify under the limitless return policy most electronics do not.

If bought less than three months ago customers are able to return their electronic products to the store for a full refund, but past this date they will not be accepted. 

2. Cigarettes

Once cigarettes have been purchased at Costco they cannot be returned. 

This applies even if the packet is unopened. 

3. Alcohol 

The same policy applies for alcohol purchased from the wholesale chain, including all spirits and wine. 

4.  Batteries

Unless the batteries purchased from Costco are faulty or customers are dissatisfied with their performance in some way they will generally not be accepted for a refund. 

5. Tires 

Costco has a generous tire check and fix policy that has amazed customers. 

It includes free-of-charge rotation, balance and inflation checks. 

However, it may surprise some members to know that you can't return tires bought at Costco.

6. Gold Bars 

Gold bars is one of the quirkier items available at the wholesaler. 

If you purchase the investment item here be sure you're comfortable with your choice as they are not returnable. 

7. Gift cards

Costco sells gift cards for other retailers, offering prices that are less than face value. 

This may seem like a good deal but if you change your mind they are non-refundable.

8. Costco Shop Cards

The same principle applies to gift cards for Costco itself, which are non-refundable to the purchaser and not redeemable for cash if received as a gift.  

However, you can use the gift cards for any purchase in the store from groceries to electronics.