New SIM card required

Ronald363  Please read this article: https://help.smarty.co.uk/en/articles/1215856-changed-your-device-and-need-a-different-sim

If you mean that you have lost a sim or broken it/had it stolen, then read: https://help.smarty.co.uk/en/articles/1215834-what-to-do-if-your-sim-card-gets-lost-or-stolen