There are a number of ways to put different phones on a non native network. One of the easiest is combining the device from one carrier with the network of another one. With gsm it works like this:
Tmobile phones will work on Tmobile mvnos without unlocking including Tuyo and Simple Mobile. Truphone may be possible. Not tested at this time.

Att phones will work with Att mvnos including: Red Pocket, Jolt gsm, H20 gsm, Air Voice Gsm, Pure Talk,
and others.

The assumption is that mvno phones will work on other mvno networks.

This cannot be done with Tracfone or Net10 (regular or unlimited). Net10 Unlimited is a Tmobile mvno but it has no byod capability with Tmobile or other Tmobile mvno phones, unlocked or not.