Sim - Why Is My Phone Saying Invalid

Most “Invalid SIM” errors resolve with cleaning, reseating, or restarting. If not, the next likely cause is a deactivated SIM (contact carrier) or a software glitch (reset network settings). Persistent issues after testing with another SIM point to hardware damage, requiring professional repair.

Work through these steps in order, starting with the easiest solutions. why is my phone saying invalid sim