[Windows Central Question]

Is it possible to sync two phones, so that if you send a text from your phone, to a friend, the text is also sent to a third phone?

[jmshub]

If you use a third party messaging service like Skype, whatsapp, Facebook Messenger, or other, it is easy to do.

With SMS or MMS, it isn't a functionality of the phone you use, it depends on whether your cell provider allows duplicate SIM cards.