Concerns about data storage and privacy were among the issues that held up the transfer of name-matching duties from the airlines to the government, which was mandated by Congress in 2004.

While many of those objections have been addressed by narrowing the scope of the information collected, there are still concerns about the quality of the watch list data.

“To be precise, we support the fact that the government is now trying to make its matches more accurate,” said Marc Rotenberg, executive director of the Electronic Privacy Information Center, which has been advocating for stronger privacy protections since Secure Flight’s inception.

“The problem with Secure Flight is that there’s still not adequate transparency or redress for people who are placed on the list,” Mr. Rotenberg said. “As we know from the latest report from the inspector general, the list is riddled with errors.”

The change will probably also create frustrations for people who go by different names and have to standardize the name listed on their passport, driver’s license and possibly frequent-flier accounts.

“I’ve got Francis on my passport but I’ve always gone by Frank — my state I.D. and all of my frequent-flier accounts are Frank,” said Frank Ritchotte, who handles logistics for an audio and visual equipment manufacturer and flies about 150,000 miles a year.

“Now I have to go back and change everything to Francis, which is going to be a pain,” he said.

Complicating matters, he said, “I’m a ‘Jr.’ as well. None of my documentation says ‘Jr.’ except my passport.”

Mr. Ritchotte said he heard about the coming change through his company’s travel department, but felt the information released by the T.S.A. so far had been confusing.

“There hasn’t been a clear message about what you have to do and exactly when you have to do it,” he said. “It’s another thing that’s a hassle.”

Among the concerns raised by fliers are names with hyphens, foreign characters, spaces or just initials and people who have two middle names or have not fully adopted a married name.

“Nicknames are going to be one of the bigger issues,” conceded Paul Flanigan, a spokesman for Southwest, which aims to start collecting the Secure Flight data in October.

Currently, many airlines do not offer a place to supply a middle name when booking online, but for now, the message seems to be: If we don’t ask for it, you don’t have to tell us.

“We’re telling customers, do business with us as you’ve always done,” said Kent Landers, a Delta spokesman. “When the systems are ready to accept the data, we’ll advise passengers.”

Credit: New York Times Service; photo credit: Getty Archives