The company said the credit would be available for people who bought either the $599 8-gigabyte, iPhone or the $499, 4-gigabyte model before Aug. 22. People who bought the phones more recently are eligible for refunds.

Those early buyers must fill out a form on Apple's Web site to have the retail or online store credit delivered to them electronically.

The credit can be redeemed only inside the United States, and cannot be used inside the iTunes store or for Apple store gift cards, according to terms listed on the company's Web site.

Apple Chief Executive Steve Jobs announced the credits a day after irking early iPhone buyers Sept. 5, when he cut the price of the expensive model by $200 and said the cheaper device would be discontinued. The price cut came less than 10 weeks after the hybrid cell phone-iPod's highly anticipated June 29 launch.

The credit claim form on Apple's Web site requires users to enter the phone number and serial number of their iPhones. They then get a text message with an access code that's needed to generate the store credit in the form of a credit number and PIN. The deadline to submit a claim for the $100 is Nov. 30.

The deadline for people who purchased iPhones between Aug. 22 and Sept. 4 to submit refund claims is Sept. 19.

Apple shares dropped 5 percent the day Jobs announced the price cut, which the company said would boost holiday sales. The stock regained some of the ground lost on Monday, when Apple announced it had sold its one-millionth iPhone.