Apple has a billion iPhones in use.

True if, as of March 2022, Apple's active iPhone installed base was approximately one billion (roughly 0.9–1.2 billion) according to Apple's disclosures or credible analyst estimates. Mostly true if the figure was somewhat outside that range but still near a billion (about 0.8–1.3 billion). Mostly false if the figure only fits when counting all Apple devices (about 1.8 billion) rather than iPhones, or if it was otherwise substantially off. False if the iPhone base was far from a billion (below about 0.6 billion or above about 1.6 billion).

Set before the research began.

1. E1 Apple Now Has More Than 1.8 Billion Active Devices Worldwide MacRumors · 27 January 2022

   “Apple now has over 1.8 billion active devices worldwide, a new record, Apple CEO Tim Cook said during today's earnings call covering the first fiscal quarter of 2022.”

2. E2 Apple Now Has More Than 1.8 Billion Active Devices Worldwide MacRumors · 27 January 2022

   “Apple's active install base includes iPhone, iPod touch, iPad, Mac, Apple TV, and Apple Watch, and it has grown from 1.5 active billion devices in January 2020 and 1.65 active billion devices in January 2021.”

3. E3 Apple Now Has More Than 1.8 Billion Active Devices Worldwide MacRumors · 27 January 2022

   “Cook did not break out numbers for individual devices, but last year said that Apple had more than billion active iPhones worldwide.”

The evidence shows more than one billion active iPhones in 2021 [E3] and over 1.8 billion active Apple devices of all types in January 2022 [E1][E2]. It gives no iPhone figure for March 2022, so it does not show whether the iPhone base fell within the 0.9–1.2 billion range for true or within the wider 0.8–1.3 billion range for mostly true.