With Text Message Forwarding, the SMS/MMS messages that you send and receive on your iPhone can appear on your Mac, iPad, and iPod touch. Then you can continue the conversation from the device you want.
Set up text message forwarding
On your iPhone, iPad, or iPod touch, go to Settings > Messages > Send & Receive. On your Mac, open Messages, choose Messages > Preferences, then click iMessage. Make sure that you're signed in to iMessage with the same Apple ID on all your devices.
On your iPhone, go to Settings > Messages > Text Message Forwarding.*
Choose which devices can send and receive text messages from your iPhone. If you're not using two-factor authentication for your Apple ID, a verification code appears on each of your other devices: enter that code on your iPhone.
As long as your iPhone is turned on and connected to Wi-Fi or a cellular network, new SMS/MMS texts can be sent and received on the devices that you added.
