UPS declared January 5, to be National Returns Day.
The delivery company said 1.3 million returned packages will be shipped back to retailers Thursday.
It is expected to be the busiest returns day in history.
— UPS News (@UPS_News) January 4, 2017
The National Retail Federation estimated that all the returns would add up to more than $260 billion in lost sales.
UPS said it would have returned nearly 6 million packages by the end of the week.