Use iPhone as a Wi-Fi hotspot
Use Instant Hotspot
You can use Instant Hotspot to provide Internet access to your other iOS devices (iOS 8 or later) and Mac computers (OS X 10.10 or later) where you’re signed in to iCloud with the same Apple ID. Instant Hotspot uses your iPhone Personal Hotspot, without you having to enter a password or even turn on Personal Hotspot.
Go to Settings , then tap Wi-Fi on your other iOS device.
Under Personal Hotspots, choose your iPhone network.
On your Mac, go to System Preferences > Network, then choose your iPhone network from your Wi-Fi settings.
When you’re not using the hotspot, your devices disconnect to save battery life. For more information, see Share your iPhone Internet connection.
Note: This feature may not be available with all carriers. Additional fees may apply. Contact your carrier for more information.
On models with Dual SIM, Instant Hotspot uses the line selected for cellular data.