Why my texts not delivering to a certain person on iPhone?
I have an iPhone X. my friend who also has an iPhone does not receive my text although I receive hers. Other people do receive my text
[Re-Titled by Moderator]
iPhone XR, iOS 17
I have an iPhone X. my friend who also has an iPhone does not receive my text although I receive hers. Other people do receive my text
[Re-Titled by Moderator]
iPhone XR, iOS 17
There are a few reasons why your texts might not be delivered to your friend's iPhone even though you can receive theirs:
iMessage Issues:

It's possible that you used their Phone Number to send an iMessage, while they might have sent an iMessage using your Apple ID. There's a chance that iMessage isn't activated for their phone number on their device.
iMessage requires phone number activation for sending and receiving messages with other phone numbers. Without activation, you can only chat with people using their Apple IDs.
Activate iMessage and FaceTime using your… - Apple Community

iMessage (Blue) -

SMS/MMS (Green) -

It will turn from Blue to Green if you have enabled "Send as SMS" and whenever your iPhone is not connected to the internet it is sent as SMS (green) to all iPhone users.
There are a few reasons why your texts might not be delivered to your friend's iPhone even though you can receive theirs:
iMessage Issues:

It's possible that you used their Phone Number to send an iMessage, while they might have sent an iMessage using your Apple ID. There's a chance that iMessage isn't activated for their phone number on their device.
iMessage requires phone number activation for sending and receiving messages with other phone numbers. Without activation, you can only chat with people using their Apple IDs.
Activate iMessage and FaceTime using your… - Apple Community

iMessage (Blue) -

SMS/MMS (Green) -

It will turn from Blue to Green if you have enabled "Send as SMS" and whenever your iPhone is not connected to the internet it is sent as SMS (green) to all iPhone users.
Why my texts not delivering to a certain person on iPhone?