According to Apple, its latest models, including the iPhone 5s, 5c, and iPad Air are not eligible for the credit, nor are first-generation devices like the iPhone 3GS or the original iPad. All other devices are eligible, however, and Apple will still recycle original models for free.
Apple's trade-in program first debuted in the United States prior to the launch of the iPhone 5s/5c, and expanded to the U.K. a few months later. It has also been brought to several other countries, including Germany, France, Canada, and Italy.
In addition to its in-store recycling program, Apple has a similar online mail-in program that requires users to send in their old iPhones before receiving credit. While the mail-in program often offers a greater value for a used iPhone, Apple's in-store program is more convenient for many customers.