No SIM

How to Fix It

1. Toggle airplane mode for 10 seconds, then restart.

   Swipe down Control Centre, airplane mode on, count to ten, off.
   If 'No SIM' stays, restart the iPhone — hold side + volume button, swipe to power off, then hold side button to power on.
   This re-registers with the carrier; many post-update 'No SIM' messages clear right here.

2. Reseat the physical SIM.

   Power the iPhone off.
   Use the SIM eject tool (or a thin paperclip) in the small hole on the side; the tray slides out.
   Take the SIM out, wipe the gold contacts with a soft, dry cloth, put it back flat in the tray, push the tray fully home.
   Power on and wait.
   A loose SIM is the most common single cause.

3. Install pending iOS and carrier settings updates.

   Settings > General > About — if a carrier settings update is available, a small dialog appears within a few seconds; tap Update.
   Settings > General > Software Update — install anything pending.
   Apple and the carrier push fixes for 'No SIM' bugs from time to time.

4. Test the SIM in another phone.

   Pop your SIM into a different phone (any unlocked Android or iPhone).
   If it reads fine there, the iPhone's SIM reader is the issue.
   If the second phone also says 'No SIM', your SIM itself is dead — the carrier will replace it free, in most cases by walking into a store with photo ID.

5. Check eSIM is enabled (eSIM-only iPhones).

   Settings > Cellular > make sure your line is on.
   If the eSIM was deleted or moved off the device, the carrier has to re-issue it — usually via a QR code in the carrier's app or website.
   On dual-SIM phones, also confirm the right line is set for cellular data and calls.

6. Call your carrier.

   If a known-good SIM works in another phone but not this iPhone, or your SIM is dead in every phone, call the carrier.
   They can confirm the line is active, send a replacement SIM if needed, or — for eSIM — push a new profile to your iPhone.
   If the line is suspended over an unpaid bill, that'll show up here, and the SIM works again as soon as it's reactivated.

7. If nothing works, the SIM reader may be failing.

   An iPhone that won't read any known-good SIM (and where eSIM is also failing if available) almost always has a hardware fault — common after a hard drop or water exposure.
   This is an Apple repair, fixed-price in most regions.
   Older iPhones near end of life with a dead SIM reader can sometimes be switched to eSIM-only if both worked before; check with Apple Support whether your model and carrier support that.