MacBook Pro unable to send SMS messages

Thankyou kindly for your thoughtful reply, and for sharing your efforts,

Wondering whether you have checked on your iPhone that not only is Message Forwarding turned on, but that in the device list for SMS forwarding your Mac is also toggled on. (Both iPhone and Mac need to be signed in to the same Apple Account.)

Set up Messages on iPhone - Apple Support

Eg: says:

"Choose other devices for SMS, MMS, or RCS messaging

Text message forwarding is built into Messages in iCloud. If you don’t want to use Messages in iCloud to save iCloud storage space or to keep messages on only some of your devices, you can still share SMS, MMS, and RCS messages between your Apple devices by using text message forwarding.

When you set up text message forwarding on your iPhone, messages you send or receive appear on your other Apple devices without requiring Messages in iCloud.

Note: Availability varies by region and carrier.

1. Go to the Settings app on your iPhone.
2. Tap Apps, then tap Messages.
3. Tap Text Message Forwarding, then turn on any devices you want to include.
4. If your iPhone is set up with Dual SIM, turn on each line. If any devices aren’t appearing in the list, see the Apple Support article Forward text messages from your iPhone to other devices.

Note: If you’re not using two-factor authentication, you need to enter a six-digit activation code that appears on the other device."

Re: "MacBook Pro unable to send SMS messages"n

SMS use cellular data, (charges may apply) ... whereas iMessages use Wi-fi.

Maybe you have an iPhone linked to your MacBook, and can send SMS via the iPhone ?

"When you sync SMS, MMS or RCS text messages on your iPhone and Mac, these messages appear on both devices. You can also send and receive these messages from your Mac. When you send a message to someone who uses a phone that’s not an iPhone, your message is sent as an SMS, MMS or RCS message"

You can scroll to "Get SMS, MMS and RCS texts from iPhone"

in Apple support's article: (link below) to see the settings needed to send SMS.

Set up Messages on Mac - Apple Support

Do you use iCloud ?

If you can’t send or receive messages using Messages on Mac - Apple Support

says:

• Install the latest macOS updates.
• Check Date & Time settings to make sure that the date and time are correct.

 Can’t change the time or time zone?

I am having the same problem. I have an iPhone and can receive SMS messages (from android user) but cannot send from MacBook. I used to be able to do this, but somewhere in the last few months or so, it quit working. At first, I thought maybe my connection wasn't good, but then noticed it was across the board with android users, and I could NOT message/sms them at all unless I use my iPhone. I use my MacBook for messaging often. How can I fix this? Please don't repeat the steps about message forwarding, etc. I've search a few times over the last few weeks, and I've done every single thing suggested from this post above, and those from 1, 3 and 4 years ago. Nothing has worked.