UPS is a little behind after the increase in online orders last week.
The courier company said on Tuesday that a small percentage of packages are delivered one or two days later than the company works to clear an accumulation of Cyber Week. UPS spokesman Steve Gaut said delivery should return to normal by Wednesday at the end of the day.
The company said it still expects most of the packages sent between Thanksgiving and Christmas to arrive on time.
"We have resolved the situation that created the delays," Gaut told CNNMoney.
Parties are always a frantic period for delivery companies. But the growing popularity of online shopping has resulted in more packages being processed and delivered.
This year's Cyber Monday was the biggest day of online shopping. In general, a record $ 6.59 billion online was spent, according to Adobe Analytics data.
Related: Holiday hiring is increasingly difficult for retailers
UPS ( predicts it will deliver 750 million of packages between Thanksgiving and Christmas. That's 5% more than last year, when UPS delivered 712 million packages. )
Seasonal challenges have been exacerbated by the fact that improving the economy has made it more difficult (and expensive) to find temporary help.
This year, UPS brought 95,000 seasonal workers for the holidays. He added the same number of people in 2015 and 2016.
And, as usual, the company has leased additional aircraft and rented more trucks to manage the high volume, and has assigned more workers to offices that are normally flooded.
"We are taking all necessary measures to ensure that we are meeting the demand of our customers, especially during this vacation period," said Gaut.
In addition, UPS has informed more than 100 parcel delivery centers in high demand areas that drivers may be required to work overtime until January 5, up to 70 hours for eight days.
The Teamsters union, which represents 250,000 UPS employees, is not satisfied with that plan. James Hoffa, president of the Teamsters, said in a letter to UPS CEO David Abney on Monday that the measure will have a "physical cost" for workers and hinders their ability to spend time with family during vacations.
UPS and the union are currently in the middle of contract negotiations.
– Chris Isidore of CNNMoney and Kaya Yurieff contributed to this report.
CNNMoney (New York) First published on December 5, 2017: 5:33 PM ET