Technology

Apple restricts adtech domains and identifiers in iOS 27 update

A software update disrupted web advertising identifiers and domain delivery across Apple devices, according to Business Insider.

Updated Oct 7, 2026 · 15:06 UTC1 reports

The short version

An Apple update within iOS 27 blocked several major advertising technology domains and identifiers across browsers powered by WebKit.[Business Insider]
The restrictions impacted firms including The Trade Desk, ID5, LiveRamp, Permutive, and Audigent, in some cases halting ad delivery entirely.[Business Insider]
Apple modified a recent beta release to untangle ad serving from identifier blocks for The Trade Desk, but affected domains may remain restricted until iOS 27.2 launches.[Business Insider]

Apple implemented WebKit blocks in iOS 27 targeting adtech identifiers and domains operated by firms including The Trade Desk, ID5, LiveRamp, Permutive, and Audigent.[Business Insider]
The restrictions completely prevented ads from serving on affected browsers in cases where companies lacked a workaround.[Business Insider]
Apple notified The Trade Desk that changes in a new iOS beta release separated its ad-serving domain from its blocked Unified ID 2.0 identifier.[Business Insider]
AdExchanger reported that Apple established a dynamically updated list capable of remotely blocking hundreds of adtech, martech, and data firms without requiring new operating system releases.[Business Insider]

According to Ad-Shield co-CEO Dustin Cha, The Trade Desk's fix is currently confined to a beta release, leaving its ad-serving domain blocked in practice until iOS 27.2 is publicly released.[Business Insider]
Adtech executives noted opacity regarding which companies Apple chooses to block, the criteria used for selection, and how frequently the restrictions may change.[Business Insider]

Outlet counts describe coverage, not independent confirmation. Reports may share a wire service or original source.