Most major electronics distributors only honor returns within 14–90 days after purchase, so it can be useful to hold onto the box during that time. However, you don't always need the box to make a return. For example, Best Buy's director of public relations Paula Baldwin tells BuzzFeed that while holding onto the original product packaging can make a return easier, it's not necessarily required. Whether you changed your mind or want to exchange a damaged item, you can return the product within the return window without the packaging or accessories — though you may have a small fee deducted from your refund.
Amazon's return policy states that it will provide a full refund within 30 days if the item arrived damaged or is still in an unopened box so there's no need to save the box! However, the policy does change from vendor to vendor so read the fine print before making a purchase.