Is there a way to add more than 20 contacts to a group message on iPhone?

Hello!

What kind of group message is it? Are the messages green or blue? If green, that number is determined by your carrier. If blue, you can have 31 members in the group message.

More detail is in this thread: https://discussions.apple.com/thread/251937098?&previousThread=255344273021

Have a great weekend!

Well that is kind of impossible. If one or more people have Android devices, the messages will be green, since iMessages are strictly between Apple devices.

Could you check again please?