The Truth About Costco's Generous Return Policy

Of course with every rule, there are exceptions. According to Mashed, Costco will refund most items without any limitations, excluding electronics, diamonds, cigarettes, alcohol, products with a limited life expectancy, and special orders. But don't be deterred from buying that new flat screen TV. You do get a 90-day grace period on all electronics to make sure you're happy with your purchase. As for cigarettes and alcohol, that really depends on your state's local laws (via Clark.com).

It might be wise to save your receipt if you plan on purchasing any diamonds from Costco. While Costco is usually lenient when it comes to their no receipt needed return policy, if you're returning a diamond over 1.00ct, you will need your receipt and all of the original paperwork as well (via The Krazy Coupon Lady).

While it may seem obvious, items that have been personalized such as picture frames, or throw rugs can't be returned (via Clark.com) since the chances of someone purchasing an item with your family's face on it is pretty slim. Other products you'll have a difficult time returning are ones with a limited life warranty. Your tires and batteries aren't going to last forever so don't get any ideas of using them for a few years and then trying to return them. 

But it's not unfeasible. Back in 2018, a woman in Santa Clara, California, was actually able to return a Christmas tree on January 4, 10 days after Christmas (via Fortune)! With enough persuasion, anything is possible.