iOS 18 is expected to be released in the second half of this year and Apple is expected to take the wraps off its next iPhone operating system update in the coming months at its annual Worldwide Developers Conference (WWDC) 2024. The iPhone maker is reportedly issuing an early version of the iOS 18 update to factories and other partners for quality control testing. This is said to be a limited version of Apple’s iOS operating system, with irrelevant applications and features removed from the user interface (UI) before it is distributed by the company.

According to a MacRumors report that cites a private X (formerly Twitter) account that is said to have a good track record of leaking details related to Apple, the iPhone maker has begun sharing a version of iOS 18 called “VendorUI” in a controlled manner with “factories and relevant vendors”.  This version contains some elements of iOS that are expected to be unveiled by the company in the coming months at WWDC 2024.

Apple develops five different versions of iOS every year, according to the report. Two of these — LLDiags (a low-level diagnostics version) and NonUI (a version for hardware engineers and calibration machines) are prepared without the iOS user interface. Meanwhile, the VendorUI (used in factories for testing) and InternalUI (used by Apple’s engineers) contain pre-production versions of iOS. Apple’s “Release” version is the one that is finally rolled out to users with all iOS visual elements, apps and features.

As most apps and features not relevant to factories and relevant vendors aren’t included in the VendorUI image, we can expect to learn more about some parts of the iOS 18 UI in the future, ahead of WWDC 2024. Previous reports suggest that Apple is working on overhauling the mobile OS interface with the upcoming iOS 18 update, including some visual elements from visionOS, Apple’s operating system for the Vision Pro mixed reality head.