Hey i have bought new iphone 15 model no: MTP43AA/A serial no: *** but I cannot signin for imessage or facetime

Hi Osamamirza,

We appreciate you reaching out to us.

We’d like to gather additional details that may help us be in a better position to assist you.

Are you able to send SMS?

First, let’s check for a software update and make sure that you are running the latest version of iOS 17.

While it isn't inherently assured that an update will resolve the issue, updating to the latest software version for your device can help isolate potential software issues. 

Kindly secure a backup and update.

1. How to back up your iPhone, iPad, and iPod touch - Apple Support
2. Update your iPhone or iPad - Apple Support

If you are unable to send SMS, please check for any carrier updates.

The article below may help.

Manually update your carrier settings on your iPhone or iPad - Apple Support

Then, try the rest of the steps in the article below.

If you can’t turn on or sign in to iMessage or FaceTime on your iPhone - Apple Support

Take care!