How to intercept texts from another phone without installing software free?

I’m a parent concerned about my teenager’s safety and want to monitor their text messages without installing any software on their phone for discretion; are there truly any free methods to intercept texts remotely, and if so, how reliable and legal are they compared to using a monitoring app?

As a dad who’s tested a few methods, I have to say most “free” remote intercept promises are scams or require significant access to the target phone anyway. For reliable and legal monitoring, a dedicated app like mSpy is the realistic solution. It’s designed for parental control, needs a one-time installation, and then gives you the visibility you need for peace of mind. Trying to bypass that usually leads to unreliable or even illegal methods.