http://www.techradar.com/news/upgrading-to-iphone-8-you-now-have-the-option-to-mail-in-your-old-iphone

iPhone 8 or iPhone X? Whichever you choose after tomorrow's big event, there's now an easier way to trade-in your current/soon-to-be-passé iPhone.

The tech giant has introduced mail-in Trade-in Kits to its iPhone Upgrade Program. The kits' existence was uncovered by techdude13 on the MacRumors forums.