iMessage is turned on in Settings, under Messages

iMessage is Apple's encrypted messaging service that sends texts over Wi-Fi or cellular data instead of through your carrier's SMS network. On iPhone 16, it is turned on by default when you set up the phone, but you can turn it off and back on in the Messages settings if needed.

To enable iMessage, open Settings, tap Messages, then toggle iMessage on. The switch will turn green when it is active. Your phone will then register your phone number and email address with Apple's servers, which takes a few seconds to a few minutes depending on your connection.

If iMessage does not turn on, or if it turns on but then turns itself off, the most common causes are a weak internet connection, an outdated iOS version, or a problem with your Apple ID. Restarting your phone and checking for iOS updates usually fixes this.

Key Takeaways

  • iMessage is enabled in Settings > Messages > toggle iMessage on, and it uses Wi-Fi or cellular data instead of SMS.
  • Your phone number and email address are registered with Apple when you turn iMessage on, which takes a few seconds to a few minutes.
  • If iMessage will not stay on, restart your phone, check that iOS is up to date, and make sure you are signed into your Apple ID.
  • When iMessage is on, messages to other iPhone users appear in blue; messages to Android users or non-iMessage phones appear in green.

What you need before turning on iMessage

You need an active Apple ID and a working internet connection — either Wi-Fi or cellular data. Your Apple ID is the account you used to set up your iPhone 16, or you can create one for free at appleid.apple.com if you do not have one yet.

You also need to be signed into your Apple ID on the phone itself. Go to Settings > [Your Name] at the top of the screen and check that you are signed in. If you see "Sign in to your iPhone" instead, tap it and enter your Apple ID credentials.

Your phone number and email address will be registered with iMessage when you turn it on. You can use either one to receive messages, and other people can message you using either one. If you want to add or remove email addresses later, you can do that in Settings > Messages > Send & Receive.

Step-by-step: turning on iMessage

Step 1: Open Settings on your home screen.

Step 2: Scroll down and tap Messages.

Step 3: Look for the iMessage toggle at the top of the screen. If it is gray, tap it to turn it on. It will turn green and show "On".

Step 4: Wait 10 to 30 seconds while your phone registers with Apple's servers. You may see a spinning circle next to iMessage during this time.

Step 5: Once the toggle is green and the spinning circle is gone, iMessage is active. Open the Messages app to start using it.

Why iMessage might not turn on

If the iMessage toggle will not turn on, or if it turns on and then turns itself back off, check these things in order: First, make sure you are signed into your Apple ID. Go to Settings > [Your Name] and look for your name at the top. If you see "Sign in to your iPhone" instead, sign in with your Apple ID password.

Second, check your internet connection. iMessage needs Wi-Fi or cellular data to register. If you are on Wi-Fi, try turning Wi-Fi off and back on. If you are on cellular, make sure you have signal bars showing at the top of the screen.

Third, check that your iOS is up to date. Go to Settings > General > Software Update and install any available updates. Outdated iOS can prevent iMessage from working.

If none of these work, restart your phone by holding the side button and either volume button until the power-off slider appears, then slide to power off. Wait 10 seconds, then hold the side button again until the Apple logo appears.

The difference between iMessage and regular SMS

When iMessage is on, messages to other iPhone users are sent as iMessages and appear in blue bubbles. These messages are encrypted end-to-end, meaning Apple cannot read them. They also use Wi-Fi or data, so they do not count against your text message plan.

Messages to Android phones or other non-iPhone devices are sent as regular SMS text messages and appear in green bubbles. These use your carrier's text message plan and are not encrypted the same way. Your phone automatically switches between iMessage and SMS depending on who you are texting.

You can turn off iMessage at any time without affecting your ability to send regular text messages. If you turn it off, all your messages will be sent as SMS instead, and they will appear in green bubbles to everyone.

Managing your iMessage contact information

When iMessage is on, both your phone number and your email address are registered and can receive messages. You can add or remove email addresses by going to Settings > Messages > Send & Receive, then tapping your Apple ID at the bottom of the screen.

If you want other people to be able to reach you by email through iMessage, make sure at least one email address is checked in the Send & Receive settings. You can have multiple email addresses registered, and people can message you using any of them.

If you change your phone number or email address, you should update your iMessage settings to reflect the change. This prevents messages from going to an old number or address that you no longer use.

Troubleshooting iMessage registration problems

Sometimes iMessage turns on but shows a spinning circle next to it for longer than a few minutes, which means registration is stuck. If this happens, turn iMessage off, wait 30 seconds, then turn it back on. Usually this clears the problem.

If registration keeps getting stuck, sign out of your Apple ID completely, then sign back in. Go to Settings > [Your Name] > Sign Out, enter your password, then go back to Settings > [Your Name] > Sign In and enter your credentials again.

If you see an error message when trying to turn on iMessage, write down the exact message and restart your phone. Most iMessage errors clear themselves after a restart. If the error persists, check Apple's System Status page at apple.com/support/systemstatus to see if iMessage services are having problems in your region.

Frequently Asked Questions

Does iMessage cost money?

No. iMessage is free to use. It sends messages over Wi-Fi or your cellular data plan, so you do not pay per message. If you are on a limited data plan, iMessage messages will count toward your data usage, but there is no separate charge for the service itself.

Can I use iMessage on an iPad or Mac?

Yes. iMessage works on iPad, Mac, and Apple Watch as long as you are signed into the same Apple ID. Messages you send from any device will appear in the same conversation thread on your iPhone 16. You can turn iMessage on or off separately on each device in that device's Messages settings.

What happens to my messages if I turn iMessage off?

Your existing iMessage conversations stay in the Messages app, but new messages will be sent as regular SMS text messages instead. They will appear in green bubbles. If you turn iMessage back on later, new messages will be iMessages again, but old SMS messages will not convert back to iMessage.

Why are my messages showing as green instead of blue?

Green bubbles mean the message was sent as SMS, not iMessage. This happens when you are texting an Android phone, a non-Apple device, or an iPhone that does not have iMessage turned on. It can also happen if iMessage registration failed on your phone. Check that iMessage is on in Settings > Messages and that you have an active internet connection.

Can I turn off iMessage for just one contact?

No. iMessage is either on for all contacts or off for all contacts. However, your phone will automatically send SMS to any contact that does not support iMessage, so you do not need to manually switch. If you want to force a conversation to use SMS only, you can turn off iMessage entirely, but there is no per-contact setting.