The iPhone Duo is reportedly facing production difficulties ahead of its October launch, with early output expected to be limited. A person said to be close to Foxconn's supply chain told China's Jiemian News that final assembly yields for Apple's first foldable iPhone were only slightly above 60% as of September 17. The source said that, under Apple's current quality standards, it could take another six months to a year for the assembly line to reach a mature yield.

According to the source, Foxconn is repeatedly adjusting equipment, assembly processes, and production settings as it makes the iPhone Duo at scale. The source also said suppliers were waiting to see whether Apple would ease any quality requirements to accelerate production. The problems apparently extend beyond final assembly, as Samsung Display's foldable OLED panels and hinge components had experienced low yields, delayed deliveries, and design changes.

A supply chain source also told Jiemian News that Apple's global stocking target for the iPhone Duo in 2026 is approximately six million to eight million units. The publication compared that figure with typical shipments of 20 million to 30 million units over a full product cycle for an individual iPhone Pro or Pro Max model. Apple unveiled the iPhone Duo on September 9, with pre-orders scheduled to begin October 16 and availability following on October 23.