The shipping giants blamed their tardiness on heavy holiday shipping volume and bad weather in some parts of the country.
"UPS understands the importance of your holiday shipments," United Parcel Service said in a statement Wednesday. "UPS is experiencing heavy holiday volume ... the volume of air packages in our system exceeded the capacity of our network immediately preceding Christmas so some shipments were delayed."
The company did not make pickups or deliveries on Christmas Day. UPS did not disclose how many packages were delayed.
A FedEx spokesman told the Associated Press that some customers would be able to pick up delayed packages at FedEx Express centers.
[Update, 9:20 a.m. PDT Dec. 26: In an emailed statement, FedEx said the company "experienced no major service disruptions in the week before Christmas despite heavy volume. Every single package is important to us, and we will continue to work directly with customers to address any isolated incidents."]
Inquiries seeking comment from UPS were not immediately returned Thursday.
Customers grumbled on social media about the late shipments.
One of our missing "overnight priority" boxes just came 2 days late from FedEx. Now just waiting on the late box from UPS. #UPSfail— Kristen (@abba_ks) December 26, 2013
Headline: “UPS, FedEx: Some gift deliveries late”. “Poor weather and volume of packages”? You couldn’t maybe plan for this? You had ONE JOB.— Noah Witherspoon (@mahalis) December 26, 2013