What To Do When Your iPhone Says No SIM

My iPhone Says No SIM
iPhone SIM card is not recognized.

From time to time, your iPhone may stop connecting to cellular phone networks, preventing you from making and receiving calls or using wireless data. There are a number of reasons why this can happen, including that the iPhone doesn't recognize the SIM card.

You'll know this is happening if a message on the home screen of the iPhone says No SIM Card Installed. You'll also notice that in the top left corner of the screen, the carrier name and signal bars/dots have been replaced by No SIM or Searching.

In many cases, this problem is caused by your SIM card becoming slightly dislodged. Fixing this problem requires no more than a paper clip. Even if that's not the problem, most fixes are pretty easy.

Locating the SIM Card

Look for the hold button and the headphone jack at the top of the original iPhone, 3G, 3GS models. You'll find a slot with a tiny hole in it. This is the tray that holds the SIM card.

On the iPhone 4 and newer, the SIM tray is on the right side of the phone. The iPhone 4 and 4S use a microSIM, while later models have a nanoSIM, a slightly smaller, more modern version of the SIM card. 

Re-Seating the SIM Card

To re-seat, the SIM card in its slot, get a paper clip (or, as Apple cheekily calls it, the "SIM card removal tool"), unfold it, and gently push one end into the hole in the SIM card tray. This will pop the tray out of its slot. Push it back in and make sure it's firmly seated.

After a few seconds (wait up to a minute), the No SIM Card Installed error should disappear and your regular bars and carrier name should re-appear in the top left corner of the iPhone's screen.

If it doesn't, fully remove the SIM. Make sure it—and the slot it sits in—aren't dirty. If they are, clean them (blowing into them is probably OK, but a shot of compressed air is always best) and reinsert the SIM.

RELATED: What is an iPhone SIM Card?

Update iOS

If reseating the SIM card didn't work, next you should check to see if there's an update to the iOS, the operating system that runs on the iPhone (connect to a Wi-Fi network and have a decent amount of battery life before you do this). If so, install it and see if that solves the problem. 

To update iOS:

  1. Tap Settings
  2. Tap General
  3. Tap Software Update
  4. If a new version is available, follow the onscreen instructions to install it.

Turn Airplane Mode On and Off

If you're still seeing the SIM error, your next step is to turn Airplane Mode on and then off again. Doing this can reset the iPhone's connection to cellular networks and may resolve the problem. To do this:

  1. Swipe up from the bottom of the screen to reveal Control Center
  2. Tap the airplane icon at the far left so that it's highlighted
  3. Wait a second or two and then tap it again, so that the icon is not highlighted
  4. Swipe Control Center down to hide it
  5. Wait a few seconds to see if the error is fixed.

Restart iPhone

If none of the steps so far has solved the problem, your next step is the all-purpose fix for many iPhone problems: a restart. You'd be surprised how many issues a restart can solve. To restart the iPhone:

  1. Press the hold button (on the top right of early models, on the right side of more recent models)
  2. Keep pressing it until a slider appears on the screen that turns off the iPhone
  3. Let go of the hold button and swipe the slider left to right
  4. Wait for the iPhone to turn off (it's off when the screen goes fully dark)
  5. Press the hold button again until the Apple logo appears 
  6. Let go of the hold button and wait for the iPhone to restart.

Check for Carrier Settings Update

Another potential culprit behind the SIM not being recognized is that your phone company has changed settings for how your phone connects to its network and you need to install them.

This process is easy, too:

  1. Tap Settings
  2. Tap General
  3. Tap About
  4. If an update is available, a window will pop up. Tap it and follow the onscreen instructions.

Test for a Malfunctioning SIM Card

If your iPhone still says it has no SIM, your SIM card could have a hardware malfunction. One way to test this is by using a SIM card from another cell phone and seeing what happens. Make sure to use the correct size—standard, microSIM, or nanoSIM—for your phone. If the No SIM Card Installed warning disappears, then your iPhone SIM is broken.

Make Sure Your Account Is Valid

It's also possible that your phone company account isn't valid. In order for your phone to be able to connect to a phone company network, you need a valid, active account with the phone company. If your account has been suspended, canceled or has some other problem, your may see the SIM error. If nothing else has worked so far, it's worth confirming that your account is OK.

If Nothing Works

If all of these steps don't solve the problem, it's likely that you've got a problem that you can't fix. It's time for a trip to your closest Apple Store or your phone company store, or to call tech support.

RELATED: How to Make an Apple Store Appointment