Apple has imposed a strict limit of two iPhone Duo pre-orders per customer across its worldwide online storefronts.

The restriction applies to every colour and storage configuration, and attempting to place three or more units in an Apple Store cart triggers an automated checkout message reading: "A maximum of 2 iPhone Duo can be purchased per customer. Please adjust the total quantity of iPhone Duo in your order before checking out."

Hypebeast reports the cap spans major international markets including Japan, Spain and the United Kingdom, while channelnews.com.au notes the US is covered as well, with no confirmation yet on whether Australia is affected.

When pre-orders first opened on October 16, early buyers in Reddit's iPhone Duo community successfully ordered more than two units, so the lockdown marks a clear reversal of Apple's initial approach.

The cap is a direct response to what Apple itself called "nothing short of extraordinary" demand for its first foldable smartphone.

Initial stock sold out within minutes of pre-orders opening on October 16, and estimated shipping dates slipped to January 22, 2027 for new orders — meaning customers who missed the first window face roughly a three-month wait.

The staggering early momentum effectively overwhelmed Apple's standard fulfillment queues and forced a recalibration of how the launch is handled, according to Hypebeast.

Apple has not officially explained the restriction, but channelnews.com.au reports the move appears designed to discourage scalpers, with resale listings already appearing on eBay at asking prices above US$5,000.

It remains unclear how effective the cap will be against determined resellers.

Hypebeast notes that Apple has not explained how it prevents scalpers from simply creating fresh accounts or cycling through different credit cards to order more than two devices, and neither outlet could confirm exactly when Apple introduced the restriction or how long it intends to keep it in place.

For buyers who want a device sooner, there are alternatives: channelnews.com.au reports that mobile carriers may have availability and that Apple's online store occasionally releases stock from cancellations, while Hypebeast reports Best Buy lists a November 10 pick-up and shipping date for the 512GB model and December 14 for the 256GB version — both well ahead of Apple's own timeline.

There is a small silver lining: some customers have reported their initially delayed shipping estimates unexpectedly moving to earlier delivery slots, so early orders may improve.

The demand surge has also drawn competitive attention — Samsung is reportedly planning six foldable and slideable phones in 2027 to counter the iPhone Duo, a sign Apple's first foldable is reshaping the market even before it reaches customers' hands.