SIM Card Not Detected: What to Do to Get Your Signal Back?

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A SIM card not detected shows up as a message like “No SIM” or “Invalid SIM”, and the phone loses its mobile signal. The cause ranges from a badly seated card to an inactive plan, a carrier lock or outdated software. Restart the phone first, then reseat the card: those are the two simplest fixes.

Common symptoms and causes

• iPhone: an “Invalid SIM” or “No SIM” alert.
• Android: a “No SIM card detected” message.
• Pixel: the SIM is greyed out and labelled “No SIM”, which means it is missing or inactive.

Samsung lists four causes: a badly inserted card, dirt on the card or the tray, a software bug or outdated firmware (the phone’s internal software), and wrong network or carrier settings. Apple adds an inactive plan, an iPhone locked to a carrier, and a tray that is not fully closed or does not fit.

Good to know: if the phone cannot see its storage card instead, follow our guide on a memory card not detected.

Before you start

The steps in this guide come from Apple, Samsung and Google. For a SIM card not detected on a Xiaomi or another brand, labels and menus may differ.

What to prepare and check:

• A SIM ejector tool or a paperclip.
• Your plan: confirm with your carrier that it is active. This is the first check Apple asks for.
• The iPhone’s lock status: open Settings > General > About. “No SIM restrictions” means the iPhone is not carrier-locked.
• Without that line, the iPhone works only with its original carrier. Another carrier requires removing the carrier lock, explained in our guide on removing the carrier lock from an iPhone stuck on one carrier’s SIM.

If your phone uses an eSIM (a built-in SIM with no card to insert), go to the eSIM section further down.

Tip: keep your SIM PIN code handy. The phone usually asks for it again after a restart.

Warning: Solution 5 erases data. Back up first: write down your Wi-Fi passwords and your APNs (the carrier’s internet access settings). You will lose saved Wi-Fi networks and, depending on the phone, Bluetooth pairings, VPNs and APNs.

Warning: do not open the phone to reach the SIM reader. Opening the device can void the warranty, so check the warranty end date first.

Solution 1: restart the phone

SIM card not detected on iPhone

1. Restart the iPhone.

SIM card not detected on Samsung

1. Hold the side button (Power).
2. Tap Power off.
3. Wait for the phone to shut down completely.
4. Turn the phone back on with the Power button.

Google Pixel

1. Turn the phone off without using the restart option.
2. Wait 30 seconds.
3. Turn the phone back on.
4. Open Settings > Network & internet > Airplane mode.
5. Turn Airplane mode off if it is on.

Once the phone is back on, the message should be gone and the mobile signal should return.

Solution 2: remove and reseat the SIM card

Tip: open the tray over a table. A nano-SIM is tiny and easy to lose.

iPhone

1. Open the tray with the ejector tool or the paperclip you prepared.
2. Take the SIM card out of the tray.
3. Put the card back in the tray.
4. Close the tray.
5. Check that the tray is fully closed with no play.

Warning: a tray from another model or another maker may not seat properly. Keep the one that came with your iPhone.

Samsung

1. Turn the phone off.
2. Eject the tray with the tool or a paperclip.
3. Inspect the card for dirt, scratches or damage.
4. Clean it with a soft, dry cloth.
5. Place the card back, properly aligned.
6. Push the tray in all the way.

A tray that is only partly in leaves the card undetected. Then turn the phone back on.

Google Pixel

1. Push the tool or paperclip into the hole until the tray pops out.
2. Look at the condition of the card. If it is bent or damaged, your carrier can replace it.
3. Clean a dirty card with a microfibre cloth.
4. Close the tray.

After this, the phone should show your carrier’s network instead of the error message.

Solution 3: test the card in another phone

Two cross-checks show whether the card or the phone is at fault. A relative’s card will do.

Another card in your phone

1. Insert a different SIM card in your phone.
2. If you have no other card at hand, ask a carrier store to run this test.

Good to know: a locked iPhone works only with its original carrier. Test it with a card from that carrier.

Your card in another phone

1. Insert your card in another compatible phone.

Reading the result

• Your card is not detected in the other phone: ask your carrier for a replacement.
• The other card is not detected in your phone: the problem is the phone. Try Solutions 4 and 5 before considering a repair.
• Both cards work everywhere: move on to Solution 4.

Solution 4: install updates

iPhone

1. Open Settings > General > About.
2. Tap OK or Update if a carrier settings update is offered.

Samsung

1. Open the phone’s settings.
2. Install the software updates on offer.

According to Samsung, an old card may need to be swapped for a nano-SIM or an eSIM.

Google Pixel

1. Check that Android is up to date.

Once the update is installed, the card should reappear in the phone’s settings.

Solution 5: reset the network settings

Warning: this step erases data, though not the photos on an iPhone. Write down your Wi-Fi passwords and your APNs before you start. Do not confuse it with a factory reset, which erases everything.

Tip: a screenshot of your APN settings saves you from retyping them by hand.

iPhone

Apple keeps this solution for when the others have failed. It erases Wi-Fi networks and their passwords, cellular settings, VPNs, APNs and the network setups for home, work or school. Your photos and data are not erased.

1. Open Settings > General > Transfer or Reset iPhone > Reset > Reset Network Settings.

Samsung

This reset erases saved Wi-Fi networks, Bluetooth pairings and mobile configurations. Write down your APN first. The label below may vary by model.

1. Open Settings > General management > Reset > Reset network settings.
2. Confirm the reset.
3. Restart the phone.

Google Pixel

1. Open Settings > System > Reset options > Reset Mobile Network Settings.

The neighbouring option, which resets Bluetooth and Wi-Fi, deletes saved Wi-Fi networks: it is not the one you need.

After the reset, the phone should find the mobile network again. Then reconnect it to your Wi-Fi networks.

eSIM and iPhones without a tray

On an iPhone with an eSIM, Apple gives no step you can take yourself: contact your carrier.

On a Pixel, a greyed-out SIM labelled “No SIM” is missing or inactive.

1. Open Settings > Network & internet > SIMs.
2. Select the inactive SIM.
3. Turn on Use SIM.

The SIM should no longer be greyed out. On the same screen, adding a SIM also lets you transfer one from another device.

Good to know: a Pixel 8 or newer can convert a physical SIM to an eSIM, over Wi-Fi and if the carrier supports it. The physical SIM then stops working, so keep it until you have checked that the eSIM works.

If nothing works

Stop in two cases. If your card is not detected in another phone, ask your carrier to replace it. If another card stays undetected in your phone after Solutions 4 and 5, or if the alert persists after the network settings reset, the phone needs a repair.

On an iPhone, contact Apple Support. On other phones, contact the maker’s support. If your line was cut off without explanation, also read our article on the SIM swap scam before you call.

Have the phone model, its serial number, the system version and the purchase date ready.

Should the repair cost more than your phone is worth, here are three recent models to compare.

Take better care of your smartphone: our toolbox

These accessories protect your data and keep your phone in good shape, whatever the SIM problem.

Frequently asked questions

Why does my phone no longer detect my SIM card?

According to Samsung, the card is badly inserted or dirty, or the software or network settings are at fault. Apple adds an inactive plan, a carrier lock and a tray that is not fully closed. The cross-checks in Solution 3 show whether the card or the phone is to blame.

How do I reactivate a SIM card that is not detected?

Restart the phone, then remove and reseat the card. On a Pixel, an inactive SIM is reactivated with Use SIM in Settings > Network & internet > SIMs. On an iPhone with an eSIM, contact your carrier.

How can I tell if my SIM card is dead?

Test it in another compatible phone: if it is not detected there, your carrier needs to replace it. A bent or damaged card should be replaced too. Samsung notes that an old card may need a nano-SIM or an eSIM.

What should I do when my iPhone says “No SIM Card Installed”?

Check that your plan is active, then restart the iPhone. Next, remove the card, reseat it and make sure the tray closes with no play. If the message stays, look for carrier settings updates, then try another card.

Can you clean a SIM card?

Yes, with a soft, dry cloth according to Samsung, or a microfibre cloth according to Google. Apple does not mention cleaning on its support page. If the card stays scratched, bent or damaged, ask your carrier for a replacement.