“Sorry, this service is not available.” when trying to text from my iPhone iOS 16.4

Hello Hoganskid,

Thanks for connecting with Apple Support Communities.

We understand that you're not able to send messages, from your iPhone. To ensure that we're on the correct path, does this issue occur with iMessage, SMS or MMS? In either case, the following steps may be able to assist you with correcting this behavior:

1. "Try to restart your iPhone

2. Check your network connection. To send a message as iMessage or MMS, you need a cellular data or Wi-Fi connection. To send an SMS message, you need cellular network connection. If you turn on Wi-Fi Calling, you can send SMS messages over Wi-Fi.

3. Check with your carrier to see if the type of message you’re trying to send, like MMS or SMS, is supported.

4. If you’re trying to send group MMS messages on an iPhone, go to Settings > Messages and turn on MMS Messaging. If you don't see an option to turn on MMS Messaging or Group Messaging on your iPhone, then your carrier might not support this feature.

5. Make sure that your device has enough space to receive images and videos.

6. Make sure that you entered the correct phone number or email address for the contact."

More details here: If you can't send or receive messages on your iPhone or iPad

We look forward to your reply.

Best wishes.