iPhone Cellular Data Not Working? 12 Fixes That Work

Signal bars look fine, 5G or LTE sits in the status bar — and nothing loads. Or the data icon is missing entirely and every app spins. Either way, you’re stranded whenever you leave Wi-Fi.

Cellular data failures usually come down to four layers: a setting that’s off (including per-app toggles most people never see), the SIM or eSIM not being read properly, the carrier’s provisioning or your plan, or an iOS glitch that a network reset clears. The twelve fixes below work through them fastest-first, and there’s a separate note at the end for the “No Service” case, which is a different problem.

Find Your Situation

How to Fix Cellular Data on iPhone

Fix 1: Confirm Cellular Data Is Actually On

Obvious, but it’s the answer more often than anything else — a stray Control Center tap disables it silently.

1. Settings → Cellular (or Mobile Data) → make sure Cellular Data is green.
2. Dual SIM or eSIM? Check the correct line is selected as your data line, and that Turn On This Line is enabled for it.
3. If the toggle is greyed out and unresponsive, jump to Fix 11 — that’s a restrictions issue.

Fix 2: Toggle Airplane Mode, Then Restart

1. Turn Airplane Mode on, wait ten seconds, turn it off — this forces the iPhone to renegotiate its connection with the network.
2. No change? Restart the iPhone fully, wait for it to reconnect, and test.

Fix 3: Check the Per-App Cellular Toggle

The overlooked setting. iOS lets you allow or block cellular data per app — and one accidental tap leaves that app dead outside Wi-Fi while everything else works.

1. Settings → Cellular → scroll to the app list.
2. Switch on any app that isn’t loading.
3. While there, check Low Data Mode (Settings → Cellular → Cellular Data Options) — it throttles background activity and breaks some apps in ways that look like a broken connection.

Fix 4: Turn On Data Roaming (Especially Abroad)

1. Settings → Cellular → Cellular Data Options → Data Roaming.
2. Traveling? Roaming must be on or you’ll have signal and no data at all.
3. Odd but effective at home too: some users find enabling roaming briefly and restarting revives a stuck data connection — just switch it back off afterwards to avoid charges.

Fix 5: Check Your Plan and Data Cap

Carriers rarely cut data off cleanly; they throttle it to a speed where nothing loads, which looks exactly like a fault.

1. Open your carrier’s app or website and check remaining data allowance.
2. Confirm the account is in good standing — unpaid balances suspend data quietly.
3. Prepaid? Check the package hasn’t expired even if the balance looks fine.

Fix 6: Install Carrier Settings Updates

These small, invisible updates carry the network configuration your iPhone needs — and they’re easy to miss.

1. Settings → General → About, and wait on that screen for about 30 seconds.
2. If an update is available, a prompt appears — install it.
3. Restart afterwards and test.

Fix 7: Reseat the SIM (or Check the eSIM)

1. Power off, eject the SIM tray, check the card is clean and undamaged, reinsert firmly.
2. eSIM users: Settings → Cellular → tap your plan and confirm it shows as active. If it was transferred from another phone, confirm the transfer actually completed on the carrier’s side.
3. Try the SIM in another phone if you can — data working there points at your iPhone; failing there points at the SIM or the account.

Fix 8: Select the Network Manually

A useful diagnostic when automatic selection latches onto a bad tower.

1. Settings → Cellular → Network Selection → turn Automatic off.
2. Wait for the scan, then pick your carrier from the list.
3. If data returns, switch Automatic back on afterwards — it’s the better long-term setting.

Fix 9: Update iOS

1. Settings → General → Software Update — Apple regularly patches cellular bugs in point releases.
2. On no data, update over Wi-Fi.
3. Restart after installing and re-test.

Fix 10: Check the APN Settings

Mostly relevant on prepaid, MVNO, and travel SIMs, where the data profile must be configured manually.

1. Settings → Cellular → Cellular Data Options → Cellular Network (this menu only appears when your carrier allows editing).
2. Compare the APN with the one on your carrier’s website — a single wrong character kills data while calls and texts still work.
3. Some carriers push a profile automatically; if yours does, reinstalling their eSIM/profile is easier than typing it.

Fix 11: Check Screen Time Restrictions

If cellular options are greyed out or blurred, this is why.

1. Settings → Screen Time → Content & Privacy Restrictions → Cellular Data Changes → set to Allow.
2. Company or school phone? A device-management profile may enforce it (Settings → General → VPN & Device Management).

Fix 12: Reset Network Settings

The reliable heavy-duty fix — it rebuilds every network configuration without touching your data.

1. Settings → General → Transfer or Reset iPhone → Reset → Reset Network Settings.
2. Saved Wi-Fi passwords are erased, so have them handy; photos, apps, and messages are untouched.
3. After the restart, test data with Wi-Fi turned off.

Still No Data?

• Call the carrier — with specifics. Tell them data is provisioned-but-dead while calls and texts work; they can re-provision the line, check for a block on your IMEI, or confirm a local outage. That’s a five-minute fix on their side and impossible on yours.
• Test with another SIM. Borrow a working SIM: if data flows, your original SIM or account is at fault; if it doesn’t, the iPhone’s modem may be failing — Apple diagnostics will confirm.
• Carrier-locked phone? A locked iPhone rejects another carrier’s SIM even when everything else is right — our SIM Not Supported guide covers that scenario.
• Wi-Fi failing too? If both connections misbehave, start from our Wi-Fi connected but no internet guide — the causes overlap.

More iPhone & network fixes on MozPK

• iPhone No Service after update
• SIM Not Supported on iPhone
• Wi-Fi connected but no internet on iPhone
• iPhone not receiving texts
• Mobile data not working on Android

Frequently Asked Questions

Why is my cellular data not working but I have signal?

Signal bars mean your iPhone reached a tower for calls and texts; data is a separate service. The usual causes are the Cellular Data toggle being off, a per-app restriction, an exhausted data allowance, or a carrier provisioning problem.

Why does cellular data work in some apps but not others?

iOS has a per-app cellular switch under Settings → Cellular. If an app is toggled off there, it only works on Wi-Fi. Low Data Mode can cause similar app-specific failures.

Will Reset Network Settings delete my photos or messages?

No — it clears saved Wi-Fi passwords, Bluetooth pairings, and network configurations only. Your data stays intact, so keep your Wi-Fi passwords handy before running it.

Why did my data stop working after an iOS update?

Updates can reset network configurations or arrive before a matching carrier settings update. Check Settings → General → About for a carrier update, then reset network settings if data is still dead.

What’s the difference between “No Service” and data not working?

“No Service” means the iPhone can’t reach the network at all — no calls, texts, or data. Data-only failures mean the connection exists but the data service isn’t flowing, which points at settings, plan, or provisioning rather than signal.