Changing size of SIM

[4Sam]

I have bought a new iphone and inserted the smaller SIM which came with the larger SIm I've been using. How do I make it usable?

[Chalkychap]

If you bought your iPhone in the UK, it needs a nano-SIM card to work on the SMARTY Mobile network, which is the smallest push-out from the SMARTY SIM card you received.

You'll need to activate the SMARTY SIM before you can use it to call, text, use apps and browse the Internet.

Activate your SIM from your SMARTY dashboard, or online at https://smarty.co.uk/activate.

[MSF]

@4Sam If the larger sim was already working when put into your old phone, you just need to push out the central nano-sim and it should work straight away in the new iPhone.

You may need to carefully check how you fit it into the iPhone to ensure that it is the correct orientation. Look carefully at the tray and ensure that the sim fits in snugly and that the tray goes into the phone smoothly - do NOT force it.

[4Sam]

Yes, the larger sim was working. The smaller one is fitted in the new phone properly,  but the phone does not register a network and when I phone it, nothing happens. What shall  I do?

[Chalkychap]

Perhaps, the nano-SIM got damaged when you pushed it out of the working larger SIM card, or possibly when inserted it into your new iPhone, @4Sam. 

You may need to ask SMARTY for a replacement SIM card. 

https://help.smarty.co.uk/en/articles/1215834-what-to-do-if-your-sim-card-gets-lost-or-stolen