So, you inserted a SIM card, and it isn’t functioning properly. That’s truly disappointing, especially if you bought a new phone, and couldn’t wait to start using it. The solution to the problem lies in the cause, which is obvious. Unfortunately the message on the screen such as “invalid SIM,” insert a SIM card,” or “no SIM” won’t be of much help. Instead, we’ll go through a variety of common reasons why your is SIM card not working, and how to solve them.
1. Do you have the right SIM card?
Before we go any further, we need to address the obvious – SIM card sizes. Although the differences might seem minuscule between mini-SIM and micro-SIM, or even micro-SIM and nano-SIM, they are there. You physically cannot put a bigger card into a slot intended for a smaller one.
2. Did you insert the SIM card correctly?
Every SIM card has a notch in one of the corners. Depending on the model of the phone, there might be a tiny drawing of the card on the plastic near the slot. It will show you which is the right side up. On newer phones that have waterproofing features, the SIM card slot is a drawer. Make sure the card fits snuggly when you insert it.
3. Is your device unlocked?
If you bought a brand new phone from a carrier, they might have locked it. To clarify, they only allow you to use their SIM cards. That means purchasing and using a SIM card from another carrier, even if it fits perfectly and boots up, is seemingly impossible.
If you are desperate for the SIM card to work on your phone, we don’t suggest taking them to court and paying hundreds of thousands of dollars. Instead, take the phone to a third-party repair shop – they can unlock the device for a price. If you are in a hurry, you might be better off buying a prepaid SIM card.
Even though they can all access the Internet, phones might ship pre-configured to use a CDMA network instead of a GSM network, and vice versa. Another option is LTE. We talked a little about it in our what is a SIM card used for. We suggest calling the carrier’s customer service for more details on the model you purchased.
4. Do you know the PIN/PUK code?
This is a common question and one that we’ve asked our readers in the past. We answered it in our I put my SIM card in another phone what will happen article. Basically, your SIM card cannot gain its full functionality until you prove your identity by entering the PIN/PUK code during the first boot. The code can be scratched off on the full-size SIM card you received from the carrier. This applies to both postpaid SIM and prepaid SIM.
5. Does your SIM card need to be enabled online?
This ties directly with CDMA/GSM networks we mentioned. More and more carriers ship the devices with an embedded-SIM card or a SIM card that is already inserted but merely needs to be activated online. You need to visit the carrier’s website, register an account, and follow their guide for SIM card activation. Another option is scanning a QR code with your camera. If you aren’t adept at it, call their Customer Service number.
6. Is the SIM Card not working because the chip isn’t clean?
It is not uncommon for dust, dirt, grease, or debris to get stuck in the phone itself, or the golden chip on the SIM card itself. Obviously, that would prevent a seamless connection and can make the SIM card not working. Take a small piece of cotton or a Q-tip, dip it in alcohol, and wipe the area off. Don’t touch the chip with your bare hands afterward, hold it by the plastic edges.
7. Do you have a dual-SIM setup?
If so, the wrong network operator might have been chosen by accident or the card might be disabled. Do this to check.
- Open Settings.
- Tap on Network & Internet.
- Tap on SIM cards.
- Enable the SIM card you want to use by switching to ON.
Now network operators.
- Go to Settings.
- Go to Mobile networks.
- Tap on Network operators.
- Tap on Search networks.
- Choose your carrier when it appears.
- Tap on Settings.
- Tap on Cellular.
- Go to Cellular Plans.
On some iOS versions, it’s named Mobile Data or Cellular Data.
- From the list of plans, tap on one to make it Primary.
- Sometimes you might get a prompt instead of a checkmark.
Tap on Turn On This Line.
Here are a few more suggestions if the SIM card not working problem still persists. You might have to do a little research for some, based on your phone model.
- Reboot your phone.
- Insert a different SIM card to see if that one works.
- Turn Airplane Mode on, then back off.
- Check for operating system updates.
- Clean your smart device’s cache.
- Change APN protocols from IPv4 to IPv6 or vice versa if your SIM can’t access the Internet.
- Try booting your device in Safe Mode.