Apple warns customers attempting to purchase more than two iPhone Duos that they must adjust their cart quantity before checkout, according to a report from Engadget. This restriction applies globally, including the US, Japan, Spain, and the UK, with the same warning message appearing across all online stores.

In addition to the purchase limit, Apple has restricted walk-in availability for the iPhone Duo in Japan, South Korea, and the UAE, according to MacRumors. The company's online store also indicates that customers needing pickup reservations should check back later, with no official confirmation yet on U.S. walk-in policies.