Did you become a victim of the dreaded “Invalid SIM card” error? Even without a SIM card, you can use your smartphone’s camera, alarm, sound recorder, play video games, enjoy multimedia, and do a bunch of common things. But that’s not a phone any longer – you can’t call, text, or access mobile data. Luckily, you won’t have to lose the key features for long – the error has happened to a lot of folks worldwide. Best of all, many successfully solved the issue. As long as you follow the steps below, it’s almost guaranteed you will fix the “Invalid SIM card” problem as well.
1. Is your SIM card plan active?
From our experience, this is the most common reason for the “Invalid SIM card” issue. People often forget that there’s a time limit, especially if they’re using a prepaid SIM card or a pay as you go SIM card. If you stop topping up the credits, the SIM card is disabled by the carrier automatically. There is no universal time period, it’s usually anywhere between 3 and 6 months of balance inactivity. For postpaid SIM cards, if you don’t sign a new contract after the old one expires, the SIM card is disabled. The solution? Go out and buy a new SIM card that fits your needs.
2. Got the phone from another country?
Some smartphone manufacturers add a region lock. This is very common with Samsung phones, as it prevents their smartphones from being bought at a discount in a third-world country, and sold for exorbitant prices in a rich country. For you, this means that only SIM cards by carriers in that country will work on it. If you are desperate, you can get the lock removed in specialized mobile repair shops. For a fee, of course.
3. Enable, then disable Airplane Mode
Try this quick fix on both Android and iOS. Enable Airplane Mode from the quick-access taskbar. Give it about 30 seconds to 1 minute, then disable it again. This will reset the network and force it to reconnect. It’s exactly what you need to fix the SIM card visibility.
4. Restart your phone
The trouble with the invalid SIM card wasn’t fixed? Why not try the most common way to fix electronics – turn it off, and back on? Although it might seem silly – if it works and saves you from going through more steps, it’s well worth the try.
5. Insert your SIM card again
Rebooted the phone and the error persists? It’s time to remove the SIM card (follow this guide on iPhone) then insert the SIM card again. This also makes sure that you didn’t incorrectly insert the SIM card the first time. If your phone has a dual SIM feature, you can also try the other slot. Remember, it has to fit snugly. This can have two obvious outcomes.
- The SIM card not working problem is now gone. Congratulations!
- The same error is still present or has been “updated” to include a reason. For example, we’ve encountered the “Invalid SIM card. Network locked SIM card inserted.” error many times.
If the error remained identical, think about this. Did you notice any damage to the SIM card tray, such as deep cracks or a missing piece? This can cause the SIM card chip to shift slightly in the slot. If that’s the case, you’ll have to visit a repair shop or order a second-hand tray for the same smartphone model.
6. Try another SIM card
Purchased the smartphone from a certain carrier, but want to use a SIM card from another? If so, you likely can’t, since your SIM card is locked to the carrier’s network. To check whether this is the issue, find your SIM card removal tool again, and use it to open a SIM card slot. Borrow a SIM card from a friend or family member that uses the carrier you bought the phone from. You can also buy a cheap prepaid SIM card. By swapping SIM cards, you’ll get your answer. If the error is gone, it means you can only use a SIM card by that carrier. That is, unless you unlock the SIM card or rather, the smartphone itself.
7. Update your firmware or operating system
This might turn out to be a software problem rather than a SIM card problem. We suggest always having the latest stable operating system version available. Do it over Wi-Fi rather than a metered connection such as mobile data. Here’s how to check.
- Open the Settings app.
- Scroll down and tap on System.
- Tap Advanced to expand, then System update.
- If there are any, tap on Resume or Update.
- Tap Settings in your app drawer.
- Go to General.
- Tap on Software Update.
- Tap on Download and Install.
- After the download is complete, tap on Install.
If your battery percentage is low, tap on Install Tonight or Remind Me Later.
8. Try to switch networks in software
This step is crucial for those using an embedded-SIM card (eSIM) since you cannot remove it physically. We’ve already outlined the steps to search for a new network in our guide on how to change a SIM card. Follow the steps under Instructions for swapping from SIM1 to SIM2. You can also try to delete an old network before searching. Usually, you can tap and hold on its name, or tap on More or three dots in the upper right corner.
9. Radical step. Try a factory reset
The “Invalid SIM card” error didn’t vanish? Here’s a last resort – return your device to factory settings. Make sure you back up any important data beforehand. Don’t worry, the contacts saved to a SIM card won’t be gone. Proceed with these steps:
- Launch Settings.
- Select General.
- Scroll down and tap on Reset.
- When prompted, tap on Erase iPhone or Erase All Content and Settings.
- Enter your Apple ID password and/or your PIN code.
- Open Settings.
- Scroll down and tap System.
- Tap on Reset options.
- Select Erase all data (factory reset).
- Tap on Reset phone.
- Type your PIN if asked, then tap Continue.
- on the Erase everything button.
10. Your phone is defective
If nothing made a difference, not even asking your carrier for assistance, there’s something defective about your device. It’s likely the SIM card reader or the network antenna. Take it to a repair shop or if it’s outdated, use the opportunity to buy a newer model.