Powell said he foresees no major trouble, but "hiccups" are likely.
"It's a new process, and it's a far-reaching process," Powell said during an appearance at the National Press Club.
Beginning Monday, users will be able to keep their phone numbers when they change cell companies. Also, if they want to get rid of their landline phones, they can transfer the numbers to cell phones.
Industry experts expect most of the requests to come from some of the nation's 152 million wireless customers switching companies. There is no government requirement dictating how long it should take to switch numbers, but the FCC said most wireless-to-wireless requests should be accommodated within 2½ hours after the carrier has told the old company about the request to transfer a phone number. Landline-to-cell requests should take a few days, the agency said.
It could take longer if companies become overwhelmed with requests, and even a misspelled address could delay transfer of service.
"I don't think anybody expects this to go 100 percent smooth," said Jeff Maszal, research director for The Management Network Group, an Overland Park, Kan.-based communications consulting firm. "I think hiccups is probably a correct term to use."
Albert Lin, an analyst with American Technology Research, a private research firm based in Greenwich, Conn., wondered whether enough employees are trained to handle the expected volume of requests.
"These carriers currently have to address and support the needs of an industry that's 150 million users in size," Lin said. "There's not enough training. There's not enough time. Customers who are so eager that they have to (transfer) their number on the first day that it's made available by law should be patient. It may take many hours or a few days."
Howard Waterman, a spokesman for Verizon Wireless, said his company is ready to go.
"We are preparing for significant traffic, and we are hopeful that all the carriers are prepared to make this as hassle-free to the customer as possible," Waterman said. "It is an unknown, and we'll have to wait and see. It all depends on how many customers go for this at once. It's fair to say that every day we'll get better at this as an industry."
Customers who find companies unwilling to transfer their phone numbers should complain to the FCC, which will investigate and take appropriate action, Powell said. Consumers can write to the agency, send e-mails to fccinfofcc.gov, or telephone toll-free to 1-888-CALL-FCC (1-888-225-5322).
By Jonathan D. Salant