Apple has acknowledged that there is a fault with its iMessage service that prevents texts being received by former customers who switch to rival devices.
In a statement to Re/code, Apple admitted that it had experienced a glitch with iMessage and that a bug fix would be available in due course.
"We recently fixed a server-side iMessage bug which was causing an issue for some users, and we have an additional bug fix in a future software update," Apple said. "For users still experiencing an issue, please contact AppleCare."
A lawsuit was filed on 15 May by Adrienne Moore, an ex-iPhone user who noticed that text messages from her friends were not reaching her Android device when sent from an Apple device.
Moore alleges that people who leave the iOS ecosystem by switching to non-Apple products are "penalised and unable to obtain the full benefits of their wireless-services contracts".
If successful, Moore could receive up to $5 million (£3m) in damages, a figure that could be increased if other complainants get involved.
Other former iPhone owners have also reported problems with receiving communications after trading in their iPhone for an Android device.
The issue affects people who retain the same number when switching phones, as messages become trapped within Apple's cloud.
The problem can be overcome if iPhone users turn off iMessage before switching devices and remove the phone number from any other Apple devices that use iMessage.