What causes the iPhone problem "Last Line No Longer Available"?
The 'Last Line No Longer Available' Error appears when a user attempts to make a call on their newly activated iPhone 13 for the first time. This issue appears to be a bug related to the e-SIM functionality on some newer iPhones, based on previous reports. An
e-SIM is a digital SIM that enables dual-SIM functionality on newer iPhone models, such as the iPhone 13 series, iPhone 12 series, iPhone 11 series, iPhone XR, and iPhone XS/Max.
There are numerous advantages to having dual-SIM functionality and an eSIM on your phone. The occasional appearance of Last Line No Longer Available iPhone 13 is one of its disadvantages.
According to Apple's discussion forums and subreddits, the error message appears most frequently when attempting to make a call using the default SIM card from the Recent Calls log. The error message prompts the user to continue the call using the "remaining line." In this case, simply tap Call in the box on the screen to make the call. Nonetheless, it will not be sent to your normal phone number. Therefore, if you are attempting to keep your personal number and work number separate (for instance), this will create complications.