The SIM card inserted in this iPhone does not appear to be supported

Where did you buy the phone? Sounds that your phone is locked to a carrier. If so, the TESCO SIM will not work on a locked phone.

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Where did you purchase the phone? Was this an unlocked phone? Was this a new phone?

If the phone was carrier locked to another carrier (which is where this error generally comes from) you would need to contact that carrier to see if they offer unlocking, and if they do, do you qualify for an unlock. You need to provide a little more information for any further thoughts.

Alright, what did you ask Apple to sell you. Did you pay full price for the phone, or was this an out of warranty replacement? If it was an OOW replacement, was the original phone unlocked or locked to a carrier? If locked, what carrier was it?

If you purchased your phone for full price and requested an unlocked iPhone at an Apple Store then your replacement will be unlocked.

If you went through an official unlock with Vodaphone and unlocked your iPhone in iTunes your replacement will be unlocked.

If neither of the above is true then that iPhone will be locked to Vodaphone.

More than likely it was. If yours was with Vodafone and it is not accepting the Tescos SIM, then it is locked. You can contact Vodafone since you were a customer and ask them if you qualify for an unlock. If you do, follow their instructions for an unlock. Once that has been completed, you will be able to use it with the Tescos SIM.

Good luck and I hope he enjoys the iPhone. Glad to have helped.

Your phone is locked to Vodafone. You will need to contact them for unlocking before you can use the TESCO SIM.