UPS was expected to handle 1.5 million returned packages alone on Dec. 19.

They say this marked the first time that National Returns Day happened before Christmas, although shippers say they do expect another major spike in returns after New Year's.

UPS says the reason behind the large amount of returns is because people are able to shop for gifts on their phones, meaning they shop earlier, give gifts earlier, and return them earlier.

They also say people will buy gifts for themselves and end up getting buyer's remorse just before Christmas.

UPS says 79 percent of e-commerce shoppers surveyed said free shipping on returns is important when selecting an online retailer, while 44 percent said the top issue encountered when returning an item online is paying for return shipping.

UPS expects to deliver 800 million packages during the holiday season.