Hello @Garybutler2 ,
Welcome to the community,
There is no such thing as a 5G SIM card, it is just a SIM card, which unless you have a very old one, should still work. You can order a replacement SIM card, but you will have to pay £1.50 or go to an EE high street store with photo ID and ask for a replacement SIM card and that will be given to you at no cost to you.
To contact EE customer service dial 150 from your mobile phone or ring customer service for free using Skype or another phone: +44 800 079 8586 or +44 800 956 6000.
