When your sim says sim registration failed or insert sim card, it means that your MTN sim is bad and you need to do a sim swap(Welcome back). But if it says sim registration failed or insert sim and still comes up once in a while please try and backup every contact you have in that sim because the moment you do a sim swap all information on the sim will be formatted meaning that you will loose every unsaved data. It is advisable to always put the sim in another phone before finally deciding to do a sim swap,because at times when the sim is still in the process of failing it still works in some phones especially smaller Nokia phones.So Below are the requirements for doing a sim swaps
1. ID card. This can be any Identity card like National ID,Voters card, Drivers licence, Valid businees ID, work ID, International passport. ETC
2. Last sim pack if you have done sim swap before otherwise just provide your sim pack.
3. 4 frequently called numbers. For those who are using family and friends or who have once used family and friends , it will be easier if you provide the numbers that you registered as your family and friends.
4. You have to know the tariff plan you are using e.g Family and friends, Supersaver,MTN Zone, PayGo,MTN Pulse ETC.
5. You also have to know the year that you started using the number that is your year of activation. Note that MTN Nigeria started in 2001.
6. The last amount you recharged.
7. alternatively you can provide your security number, the complete 16 digits.
Now,you are good to go to any MTN walk-in center and they will give you a welcome back form to fill.
Please also note that if you want to do swap for someone, the person will write a letter of authorization stating that he/she sent you to do a welcome back with his/her full name and the number that the swap will be done on. The letter should be an official letter. The person will also give you his/her ID card that has a signature. Below is a format for the authorisation letter.
No 4 kamalu street
Okoko
Ojo
Lagos
The Manager
MTN N
Matori SC( This should be the name of the branch)
Lagos
Dear Sir/ma
AUTHORIZATION LETTER TO DO A SIM SWAP
I Mr Obi Amadi hereby authorize miss Cynthia Nwankwo to do a swap on my line 2348030000000 with her national ID.
Below are some numbers i frequently call and i started using this number in 2005 and i am using supersaver tariff plan. My last recharge card was 400.
Thanks
Mr Obi Amadi
Sign
I do hope this information is helpful. Thank you for choosing MTN.