Insert correct sim

Activate your phone or SIM card online if you purchased it with a new wireless account, an upgrade, or added a new line.
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Insert SIM card

1. Go to Device Support.
2. Select, confirm, or change your device.
3. Select View All Solutions > Insert SIM Card.

HI is your phone not accepting your sim then it mean your phone might be locked to some other network provider due to this it wont accept any other GSM sim until you unlock it .You can easily unlock the phone through online providers like ClassicUnlocking.com here they are rendering network unlock code for all mobile models at reliable cost .You first check that whether the code is available for your mobile model ,country and network provider .If yes then pay for it and unlock the phone then freely use it with any GSM sim ...

may be your sim card is very old
go to sim store and ask for new sim on same no
go with your id proof

ya they set the default sim as your phone no. so you can goto the nearest vodafone store and get a new sim on the same number and insert the same .because the phone may be locked

Make sure the sim card is inserted in there correctly and if its still not reading the sim card it might have a Bad sim card reader

Hi,
How to correct sim card error / insert sim card

Procedure to follow

Step 1: Check the sim tray or sim seater to see if it it broken, if it is, replace it
Step 2: If the sim seater/tray is not broken, clean the entire terminal.
Step 3: If the sim seater/tray is not directly on the board, trace the broken led and solder it, or you replace the broken led with another sim tray.
Step 4: If it is still not working, change the battery and put a new battery, because a virus infected battery will always give such problem.
Step 5: Finally, if the problem still persist, then check the sim card and replace with another sim card if the former is bad because a bad sim card will always display such message as insert sim card or sim card error.

Take care

First, make sure you have the SIM inserted in the phone correctly. If you do - and the phone still doesn't recognize the SIM card - you may need to replace the SIM card.

This is a common problem with some phones especially when the SIM has been transferred from one phone to another.

Just about the only way to correct it is to replace the SIM card with a new one.

You can purchase one on eBay for a few dollars instead of paying $25 at a retail outlet. Once you receive it, carefully pop it out of the card it is attached to and correctly insert it into your phone.

Put in your battery and turn your phone ON. You should see a 'No Service' message on the screen. If you do, then your phone can now recognize the new SIM card.

Look on the larger card you removed the SIM from and get the SIM number from the card. Then call your service provider and inform them you have replaced a defective SIM card with a new one in your phone. Give them the new SIM card number and in less than 1-minute your phone will be working again.

When it does, the message on the screen will change from 'No Service' to the name of your cellular provider.

Is this a new phone? If so check that you've inserted the SIM correctly and it's not SIMlocked to another network

If it's worked before remove the SIM and GENTLY clean the contacts on the phone and the SIM with a pencil eraser.

I know this sounds dum but!!
does it say
insert sim
or
insert correct sim?