How to delete the short message copied to the card?

Actually, I don't quite understand your situation

As for the storage location of short messages, some are stored on mobile phones (generally 200, depending on the memory size of mobile phones), some are stored on sim cards (generally 30, depending on the capacity of sim cards), and some can be converted into expansion cards (such as TF cards or minSD cards, but this situation is rare, mostly in the first two cases).

So you have to find out where you copied it. It seems that you said that you copied it to the sim card, and this card is to be returned to others or something.

Anyway, if the card is still available, you can delete the short messages on the card and the mobile phone.

Cards that can't communicate are installed on mobile phones, and you can edit short messages with software such as mobile phone studio through data lines.

If you leave a mobile phone card, you can read it or delete it with special software (such as magicsim) through a card reader (special).

I hope it helps.