PayPal, owned by eBay Inc., said its full functionality had returned to normal for all users. A day earlier, the service began to improve, though the company said delays persisted for some users.
The San Jose, Calif., company had blamed the woes on a software update conducted Friday, which left some users without the ability to access the site, their accounts, and online payment and other services.
PayPal and eBay executives, in a message to users posted on Thursday, said they were disappointed with the services performance and vowed to do better.
"First we want to apologize for the way this has impacted your buying and selling activity and, for many of you, your businesses," they wrote.
The message was signed by Meg Whitman, eBays president and CEO; Matt Bannick, senior vice president of global online payments for eBay and PayPals general manager; and Marty Abbott, eBays senior vice president of technology.
"Providing outstanding service is our top priority at PayPal. Although we didnt meet your expectations—or our own—in the past few days, we look forward to the opportunity to regain your faith in our service," the message said.
PayPals outages have hurt more than online sellers and buyer. eBay also relies on it as a major form of payment for completing eBay auctions. PayPal has 50 million user accounts.