@mari94 as mentioned by @kb_mv the sim card is most likely 3 hole punch. Older ones are not. Does yours punch out?
To answer your question. If you ever need to buy a new sim card (example lost a phone) and add it to your account. Never activate the new card.
Simply log into your account and click "Change SIM card"
Green arrow on picture below.
@mari94 wrote:I accidentally purchased the wrong size of sim card, and already activated it and switched providers. Can I buy a new one and just switch over the existing information?
@mari94 Sim cards now days are 3 in 1 sized. If you need a smaller one, punch out the next size. If you need a larger one and don't have the punch outs anymore they are available on amazon or better yet, a phone kiosk would probably give you one if you asked nicely. See 3 sizes in one card below....
