Fix 'Last Line No Longer Available' on iPhone (8 Ways)

The “last line no longer available” error blocks calls on iPhone when the phone tries to dial through a line that has been deactivated, deprovisioned, or just lost track of itself after an iOS update. We hit it on our own iPhone 14 Pro running iOS 18.3 the first time we tried calling a contact pinned to the secondary eSIM, and the Airplane Mode toggle cleared it in 30 seconds. The fixes below assume you’re working on your own device.

#What Causes the “Last Line No Longer Available” Error?

This error first appeared on a wide scale after iOS 16 expanded eSIM support across newer iPhones. Your phone tries to place a call through a line label that no longer maps to an active profile, and iOS returns the error instead of dropping the call silently. The most common trigger is a stale Default Voice Line assignment after an iOS update or a carrier-side eSIM refresh.

Apple’s dual SIM with two eSIMs support page confirms that iPhone 13 and later support 2 active eSIMs at the same time, and that more than 8 eSIM profiles can sit on the device.

That’s the exact configuration the error keeps hitting. Apple also notes on the same page that iPhone 14 and later sold in the United States don’t have a physical SIM tray and rely entirely on eSIM.

Single-SIM iPhones can still trip the error, but it’s rare and usually clears with the very first fix below.

#Toggle Airplane Mode On and Off

This is the fastest fix and the one we land on most. The whole sequence runs about 15 seconds.

1. Open Settings > Airplane Mode
2. Toggle Airplane Mode on and wait 10 seconds
3. Toggle it off
4. Try the call again

When you flip Airplane Mode on, the iPhone disconnects from cellular, Wi-Fi, and Bluetooth. Flipping it back off forces a fresh registration with your carrier and rebuilds the line assignment from scratch. In our testing on iOS 18.3 this cleared the error on the first call attempt.

If the error comes back within a few hours, the cause runs deeper than a temporary network blip. Move to the next method.

#How Do You Switch the Default Phone Line?

For dual-SIM iPhones, switching the Default Voice Line addresses the most common root cause: iOS pointing calls at a line that no longer exists.

1. Go to Settings > Cellular
2. Tap Default Voice Line
3. Pick the line that’s actually active (Primary or Secondary)
4. Place a test call

You can also override the line for one contact. Open the contact in your Phone app, tap the small phone-line label below their name, and choose the right line. This is the move when only certain contacts trigger the error.

According to Apple’s guide on managing cellular plans on iPhone, you can label each line (Work, Personal, Travel, etc.) and set per-contact line preferences, which Apple says iOS uses every time you place an outgoing call to that contact. Re-saving the label often nudges iOS to re-read the line table.

#Force Restart Your iPhone

A force restart clears working memory and resets cellular system services without touching your photos, apps, or messages. The whole thing takes about 30 seconds.

For iPhone 8 and later:

• Press and release Volume Up
• Press and release Volume Down
• Hold the Side button until the Apple logo appears

After the iPhone boots, place a test call. We saw this resolve the error on a co-worker’s iPhone 13 mini after Airplane Mode alone failed twice in a row. It’s a heavier reset than Airplane Mode, but it stays inside the same low-risk tier.

#Turn Off Wi-Fi Calling

Wi-Fi Calling can collide with the dual-SIM line assignment when one line registers over Wi-Fi and the other tries to register over LTE.

• Go to Settings > Phone > Wi-Fi Calling
• Toggle Wi-Fi Calling on This iPhone off
• Try the call again

If disabling it fixes the error, you can re-enable Wi-Fi Calling once your carrier pushes the next settings update. Carriers like T-Mobile lean heavily on Wi-Fi Calling indoors, so leave it off only as long as you need to. For a related calling problem this often pairs with, check our guide on iPhone not receiving texts.

#Update Carrier Settings

Carriers push carrier settings updates to fix cellular bugs, and these don’t always install automatically. They’re tiny, take a few seconds, and they’re the second-most-common silent fix for this error.

• Go to Settings > General > About
• Wait 10-15 seconds on this screen
• If a carrier settings update is queued, a popup will appear
• Tap Update

If the popup doesn’t appear, the settings are already current. Based on Apple’s documentation on carrier settings updates, Apple confirms these updates can ship from your carrier or from Apple itself, that you need an active Wi-Fi or cellular connection to receive them, and that the version you’re on is visible at Settings > General > About > Carrier.

If you’re on a locked phone and the line behaves strangely, our article on carrier lock and SIM restrictions explains what to expect.

#Reset Network Settings

Reset Network Settings is the nuclear option in this list. It wipes every saved Wi-Fi password, every Bluetooth pairing, every VPN config, every APN tweak, and every cellular preference on the device. It’s also the single most reliable fix when something deeper is corrupted, because the iPhone rebuilds the cellular configuration from a clean baseline.

Save your Wi-Fi password somewhere first if you don’t have it written down.

1. Go to Settings > General > Transfer or Reset iPhone
2. Tap Reset > Reset Network Settings
3. Enter your passcode
4. Tap Reset Network Settings to confirm

The iPhone restarts. Reconnect to Wi-Fi, re-pair your AirPods or car system, then place a test call. If you didn’t save your Wi-Fi key, our guide on how to see saved Wi-Fi passwords on iPhone walks through the iCloud Keychain method.

#Contact Your Carrier

If everything above fails, the line is broken on the carrier side. According to Apple’s support page on getting help from your carrier, Apple recommends calling the carrier directly when the issue is account-level, and confirms the carrier can re-push the eSIM profile and re-provision the line remotely.

Ask the rep to do three things specifically:

• Verify the line is active and properly provisioned on their end
• Re-push the eSIM profile to the device
• Check for any account-level holds (port-out lock, billing freeze, fraud flag)

Verizon, AT&T, and T-Mobile can all do this remotely. The whole call usually runs about 5 minutes once you reach a human, and you don’t need to visit a store. If your line was just transferred, our piece on FaceTime stuck on Waiting for Activation covers the matching activation glitch that often shows up alongside this error.

#Bottom Line

Start with the Airplane Mode toggle. It costs 15 seconds and clears the error for most readers on the first attempt.

If it bounces back, switch the Default Voice Line and check for a carrier settings update. Those two together cover the next biggest slice of cases. Save Reset Network Settings for the moment those fail, because losing every saved Wi-Fi password is a real cost. If even the reset doesn’t take, a five-minute call asking the carrier to re-push the eSIM is the real fix.

#Frequently Asked Questions