New York (CNN Business) Millions of holiday gifts are about to turn into holiday returns. January 2 will be a particularly epic day for sending stuff back, UPS predicts.

Shoppers will return more merchandise than ever following this holiday season , including a record 1.9 million packages on Thursday, according to a new UPS forecast. That would amount to a 26% increase from a year earlier.

FedEx FDX That's just for UPS; it doesn't include what the US Postal Service or shipping competitors likemay have to contend with

UPS UPS and its shipping rivals have dubbed January 2 "National Returns Day," because of the crazy amount of packages the company handles on the first work day of the new year. But returns have been mounting throughout the month: The company estimated it will end up handling more than 1 million returns per day in December, a record pace it expects will continue into the new year.

UPS attributed the big spike in package returns to a change in customer behavior: Many people buy online with the intention of returning the product if they don't like it. It's the online equivalent of bringing five sweaters into a dressing room.

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