An innovative feature awaited for iOS 27 promises to revolutionize the way users manage their Apple devices, allowing two iPhones to share the same phone number. The novelty seeks to eliminate the need for multiple numbers or accounts for those who want to use more than one device, whether to separate personal from professional use or to combine a foldable model with a traditional one. This significant change could simplify the lives of many and will be detailed below, including the crucial question of its applicability in the Japanese market.

iOS 27 feature allows you to switch between two devices with a single number

The functionality provided for in iOS 27, which makes it possible to use “two iPhones with the same number”, consists of a system where users can register a single phone number on two different brand devices and switch between them as needed. The central point of this implementation is the ability to change the active device without the requirement to acquire a new number.

Apple revealed a series of improvements for iOS 27, iPadOS 27 and macOS 27 Golden Gate during WWDC 2026, which took place in June. Among the improvements announced was the feature that will allow users to alternate the use of the same phone number between two different iPhones.

The proposal is that the two iPhones are registered under a single number and that the user alternates which one is active to receive calls and messages, instead of both ringing simultaneously. However, this functionality is still in the beta phase, and its scope in the final version has not been fully defined. The expectation is that iOS 27 will be officially launched in the autumn of the northern hemisphere, and the definitive inclusion of this feature is one of the most anticipated points.

Practical scenarios for using the new system on different iPhone models

The possibility of using two iPhones for different purposes represents one of the most obvious uses of this innovation. A user can choose to use a Pro model, known for its high-performance camera, in everyday life, and switch to a lighter model, such as an iPhone Air, during travel, without having to change phone numbers.

Compatibility with the long-awaited foldable iPhone also proves to be an important benefit. International media reports suggest that this could be a convenient alternative for those who plan to use both the foldable model, scheduled for launch this fall, and the conventional iPhone 18 Pro. With this functionality, the number displayed for the contact will not change, even if the device is changed.

Historically, managing the same phone number on two iPhones was a complex process. The ability to use different devices for different purposes, while maintaining the unification of the phone number, is what gives this new feature its innovative and practical character.

Carrier Compatibility Challenges and Scenario for Users in Japan

A crucial aspect to be considered is the system’s dependence on support from telephone operators. International press reports indicate that the feasibility of sharing a number between two iPhones may depend on operator adoption, and its functionality in the beta version is still unclear.

For Japanese consumers, this point generates the greatest uncertainty. Although there are already solutions for multiple numbers, such as Dual SIM, which allows two numbers on a single device, and the option to share the same number between an iPhone and an Apple Watch, the new functionality reverses this logic. Instead of two numbers on one device, it offers the ability to *switch* between two devices using a *single* number.

As with previous features involving number management, support from operators will be a fundamental prerequisite. Apple’s own information about Dual SIM already specifies the need for an eSIM-compatible carrier and, in some cases, SIM unlocking. The ability to use the same number on two iPhones will therefore depend on the decision of operators such as Docomo, au, SoftBank and Rakuten Mobile to adopt and support the new system.

At the moment, there is no conclusive data that guarantees the functionality will work in Japan. The most likely scenario is that users will wait for the official release of the stable version of iOS 27 and specific announcements from each operator about their compatibility with the feature.

Future Prospects and Challenges of Single Number Feature for Multiple iPhones

iOS 27 is expected to introduce an option that will make it easier to switch between two iPhones using a single phone number. For those who already have two iPhones or plan to use a foldable model in conjunction with a traditional one, the unification of their numbers represents a great attraction and a welcome simplification.

However, the definitive implementation of the feature directly depends on support from operators, and the exact status of its functionality in the beta version is still unclear. Availability in Japan, for example, will be linked to both the official launch of iOS 27, scheduled for autumn in the northern hemisphere, and compatibility announcements by local operators. Interested parties should monitor these two points.