Thanks for your first post and welcome to our forums page.
As the SIMs we have sent out over the past couple of years are multi SIMs, these fit in any handsets. Will you SIM fit in your new phone?
If the SIM slot is too small, please take a look at the SIM you have and double check to see if you can pop the middle out to make it smaller. If you can't or if you need a bigger SIM, please let us know and we can send you a replacement.