iMessage Not Working? Here's How to Fix It (Updated for iOS 18 & iOS 26)

Contending with a non-working iMessage function is one of the most frustrating iPhone problems—partly because the symptoms look so different from each other. Messages stuck on "Not Delivered." A blue conversation that suddenly goes green. "Waiting for Activation" that never resolves. Photos that refuse to send. This guide covers every major iMessage failure, organized by symptom, so you can jump straight to your problem and fix it fast. Every step below has been verified against iOS 18 and iOS 26.

Try These Quick Fixes First

Before diving into symptom-specific steps, run through these five fast fixes. One of them resolves the majority of iMessage issues in under two minutes.

1. Toggle Airplane Mode on, wait 10 seconds, toggle off. ⏱ 10 seconds. Forces your iPhone to re-establish its network connection.
2. Force-close the Messages app and reopen it. ⏱ 5 seconds. Swipe up from the bottom (or double-press the Home button), swipe Messages away, then reopen.
3. Toggle iMessage off and back on. ⏱ 30 seconds. Go to Settings > Apps > Messages > iMessage, flip it off, wait five seconds, flip it back on.
4. Restart your iPhone. ⏱ 1 minute. The method varies by model—Apple's restart guide covers every current iPhone.
5. Check Apple's System Status page. ⏱ 15 seconds. Visit apple.com/support/systemstatus. If the iMessage indicator is yellow or red, there's a live outage—wait it out. Nothing you do on your end will fix a server-side problem.

If none of those did it, find your specific symptom below.

iMessage Says "Not Delivered" (Red Exclamation Mark)

That red ! next to a message means iMessage tried to send and failed. Here's how to work through it, starting with the most common causes.

Step 1: Check your internet connection ⏱ 30 seconds

iMessage requires either Wi-Fi or cellular data. Open Safari and try loading any webpage. If it fails, your connection is the issue—not iMessage itself. Fix your connection first, then try resending.

Step 2: Tap the red ! and choose "Try Again" ⏱ 5 seconds

Sometimes a single retry is all it takes, especially if you hit a brief signal dropout.

Step 3: Send as a text message instead ⏱ 5 seconds

Tap the red ! and choose Send as Text Message. This pushes the message through as a standard SMS over your cellular network. It'll show as a green bubble, but it'll get there.

Step 4: Check whether the recipient blocked you ⏱ 2 minutes

If iMessage consistently fails to deliver to one specific person—but works fine for everyone else—there's a chance they've blocked your number. Try calling them. If the call goes straight to voicemail every single time without ringing, that's a signal (though not definitive proof) of a block.

Step 5: Check whether the recipient switched to Android ⏱ 2 minutes

When someone switches from iPhone to Android without deregistering their number from iMessage, Apple's servers still try to route your messages to them as iMessages—and fail. The fix is on their end: they need to use Apple's Deregister iMessage tool. You can't force this yourself, but you can let them know.

Step 6: Reset Network Settings ⏱ 3 minutes

If "Not Delivered" is happening with multiple contacts, a corrupted network configuration could be the culprit. Go to Settings > General > Transfer or Reset iPhone > Reset > Reset Network Settings. Note: this erases saved Wi-Fi passwords, so have those handy before you proceed.

iMessage Waiting for Activation

"Waiting for Activation" means iMessage is trying to register your phone number with Apple's servers but hasn't finished. It can be a quick fix or a 24-hour wait—here's how to tell which.

Step 1: Confirm you have a working connection ⏱ 30 seconds

Activation requires either Wi-Fi or cellular data. The same Safari test works here: if a webpage won't load, fix your connection first.

Step 2: Set Date & Time to automatic ⏱ 30 seconds

This one catches a lot of people off guard. If your iPhone's clock is wrong, Apple's activation servers can reject the request. Go to Settings > General > Date & Time and make sure Set Automatically is toggled on.

Step 3: Toggle iMessage off, restart your iPhone, toggle back on ⏱ 2 minutes

Go to Settings > Apps > Messages > iMessage and turn it off. Power your iPhone completely off, wait 10 seconds, turn it back on. Then re-enable iMessage. This forces a fresh activation attempt.

Step 4: Verify your carrier supports the activation SMS ⏱ 1 minute

iMessage activation sends a background SMS to Apple's servers—this is how Apple verifies your phone number. Some carriers charge for this SMS, and a few international or prepaid carriers block it entirely. If you're on an MVNO (a smaller carrier that runs on a major network's infrastructure), check with them to confirm SMS is enabled on your plan.

Step 5: Wait up to 24 hours

Apple officially states that activation can take up to 24 hours after carrier verification. If you've done everything above and it's still pending, give it time before escalating.

Step 6: iOS 26 eSIM note

If you set up a new iPhone with an eSIM and skipped the iMessage activation step during initial setup, iMessage won't activate automatically when you add the eSIM later. The fix: go to Settings > Apps > Messages > iMessage, toggle it off, then back on. This manually triggers the activation process.

Step 7: Still stuck after 24 hours?

Contact your carrier first to confirm international SMS is enabled on your account. If they confirm it is and activation still fails, contact Apple Support directly—there are rare cases where Apple's servers have a block on a specific number that only Apple can clear.

Why Are My iMessages Green Instead of Blue?

Blue bubbles mean iMessage—encrypted, sent over the internet, Apple-to-Apple. Green bubbles mean SMS, MMS, or RCS—sent over the cellular network. Here's why your messages might have gone green and what to do about it.

The most common reasons for green bubbles

• The recipient is on Android. iMessage only works between Apple devices. If someone switched to Android, your messages to them will always be green.
• The recipient has iMessage turned off. Even iPhone users can disable iMessage. If they've turned it off, you'll get green bubbles.
• You lost your internet connection. No Wi-Fi or cellular data means no iMessage. iOS will fall back to SMS automatically.
• Apple's iMessage servers are down. Check Apple's System Status page.
• You just set up a new device. iMessage may not have finished activating yet. See the "Waiting for Activation" section above.

What changed with RCS in iOS 18

iOS 18 added RCS (Rich Communication Services) support for iPhone. RCS is a step up from SMS—it supports read receipts, higher-quality photos, and typing indicators when messaging Android users. But RCS messages still show as green bubbles. Blue = iMessage only.

How to get blue bubbles back

Make sure both you and the recipient have iMessage enabled and an active internet connection. If the conversation has been green for a while, starting a new message thread can sometimes prompt iOS to re-check whether iMessage is available for that contact.

If the recipient is on Android, there's no way to get blue bubbles—that's just how iMessage works. RCS is the best you'll get for cross-platform messaging.

iMessage Not Working in Group Chats

Group chat failures have their own set of causes. Here are the three most common.

Problem 1: Someone in the group switched to Android

A single Android user in a group chat breaks the iMessage thread for everyone. You'll see that person's messages in green, and the whole conversation may behave erratically—split threads, missing messages, or delivery failures.

The fix: Start a fresh group conversation with the same people. When you create a new group, iOS checks each contact's messaging capabilities and routes accordingly. The Android user will be included via SMS/MMS or RCS, and the iMessage users will stay on iMessage.

Problem 2: You were removed from the group (or left it)

If you're no longer receiving messages in a group chat, check whether you see "You left the conversation" or "You were removed from the conversation" in the thread. If so, you'll need to be re-added by another participant—you can't re-add yourself.

Problem 3: Photos and videos aren't sending in group chats

When a group chat includes non-iMessage users (green bubble), it switches to MMS—and carriers impose strict size limits on MMS attachments, typically 1–3 MB. A photo taken on a modern iPhone can be 5–10 MB or more.

The fix: Go to Settings > Apps > Messages and enable Low Quality Image Mode. This compresses images before sending and usually gets them through MMS limits. For video, you may need to use AirDrop, a shared iCloud link, or a third-party app like WhatsApp instead.

iMessage Not Sending Photos or Videos

If photos and videos fail specifically—even when text messages go through fine—here's where to look.

Check available storage ⏱ 30 seconds

Go to Settings > General > iPhone Storage. If you're running low (under 1–2 GB free), iMessage may struggle to process and send media. Clear out some space and try again.

Enable Low Quality Image Mode ⏱ 15 seconds

Go to Settings > Apps > Messages > Low Quality Image Mode and toggle it on. This reduces image file size before sending—useful when you're on a slow connection or sending to non-iMessage users with MMS size limits.

Check that cellular data is enabled for Messages ⏱ 30 seconds

If photos fail only when you're on cellular (but work fine on Wi-Fi), Messages may not have cellular data permission. Go to Settings > Cellular, scroll down to Messages, and make sure it's toggled on.

For large videos

iMessage has a size limit for video attachments. For longer clips, share via iCloud link instead: in the Photos app, select the video, tap the share icon, and choose Copy iCloud Link. Paste the link into your message—the recipient can stream or download it without the file size restriction.

iMessage Not Working on Mac or iPad

iMessage on Mac and iPad depends on a few settings being aligned across all your devices. When it breaks, it's almost always one of these.

Step 1: Verify you're signed in with the same Apple Account ⏱ 1 minute

On iPhone: Settings > [Your Name] — confirm your Apple Account email. On Mac: Messages > Settings > iMessage — confirm the same email is signed in. On iPad: Settings > [Your Name] — same check.

A mismatch here means your devices can't sync messages with each other.

Step 2: Check Send & Receive settings on each device ⏱ 2 minutes

On iPhone: Settings > Apps > Messages > Send & Receive On Mac: Messages > Settings > iMessage > You can be reached for messages at On iPad: Settings > Apps > Messages > Send & Receive

Make sure your phone number and Apple Account email are both checked under "You can be reached by iMessage at" on every device. If your phone number is missing from Mac or iPad, that's why those devices aren't getting your messages.

Step 3: Turn on Messages in iCloud ⏱ 1 minute

Messages in iCloud keeps your message history synced across all devices. Enable it on each device:

• iPhone/iPad: Settings > [Your Name] > iCloud > Messages — toggle on
• Mac: Messages > Settings > iMessage > Enable Messages in iCloud

Step 4: Set up Text Message Forwarding for SMS ⏱ 2 minutes

iMessage works natively on all Apple devices, but SMS and RCS messages only arrive on your iPhone. To see them on Mac or iPad too, enable Text Message Forwarding: Settings > Apps > Messages > Text Message Forwarding, then toggle on each device you want to receive SMS on.

Step 5: Sign out and back in on the affected device ⏱ 3 minutes

If messages appear on your iPhone but not on a specific Mac or iPad, sign out of iMessage on that device, restart it, and sign back in. On Mac: Messages > Settings > iMessage > Sign Out. On iPad: Settings > Apps > Messages > Send & Receive > [Your Apple ID] > Sign Out.

iMessage Not Working After Switching Phones or Setting Up a New Device

Switching iPhones—or setting up a new one—is one of the most common triggers for iMessage problems. Here's the checklist.

Step 1: Update to the latest iOS version ⏱ 5 minutes

Go to Settings > General > Software Update. Running the latest iOS eliminates a whole category of known activation bugs.

Step 2: Verify your cellular line is active ⏱ 30 seconds

Go to Settings > Cellular and confirm your line is toggled on. If you transferred a SIM or eSIM and the line isn't active, iMessage can't activate.

Step 3: Toggle iMessage off and back on ⏱ 30 seconds

Settings > Apps > Messages > iMessage — off, wait five seconds, back on. This triggers a fresh activation attempt with your current SIM or eSIM.

Step 4: Confirm your phone number is selected in Send & Receive ⏱ 1 minute

Go to Settings > Apps > Messages > Send & Receive. Your phone number should appear under "You can be reached by iMessage at" and be checked. If it's missing, tap it to add it.

Step 5: iOS 26 eSIM caveat

Setting up an eSIM after completing initial iPhone setup is a known trigger for iMessage activation failure in iOS 26. iMessage won't auto-activate when an eSIM is added post-setup. The fix is the same as Step 3: manually toggle iMessage off and back on after your eSIM is active.

When to Contact Apple Support vs. Your Carrier

Most iMessage problems are software or settings issues you can fix yourself. But when self-service runs out, knowing who to call saves you a lot of time.

Contact Apple Support if:

• iMessage won't activate after 24+ hours and your carrier has confirmed SMS is working
• You see persistent error messages that don't match any of the symptoms above
• iMessage works on another device signed into the same Apple Account, but not on your iPhone—this can indicate a server-side issue that only Apple can resolve
• You suspect your phone number is on Apple's iMessage block list (rare, but it happens—usually after a device was reported stolen or an account was flagged)

Contact Apple Support →

Contact your carrier if:

• You can't send or receive SMS or MMS at all (not just iMessage)
• You're getting activation errors that reference SMS failure
• You're on a prepaid or MVNO plan and aren't sure whether messaging is included
• You recently ported your number and messages aren't routing correctly

Your carrier's support line is the right first call for anything that looks like a network or plan issue. Apple can't fix a problem that lives on the carrier's side.

The Bottom Line

The vast majority of iMessage problems come down to three things: a lost internet connection, an activation that didn't complete, or a settings mismatch across devices. Toggle iMessage off and back on, check your connection, and make sure your iOS is up to date—those three steps alone resolve most issues in under two minutes.

If your iMessage problems keep coming back, it's worth checking whether your carrier plan is part of the issue. Some prepaid and MVNO plans have messaging limitations that can interfere with iMessage activation and SMS fallback. Navi's Plan Finder can help you compare options across carriers—it's completely free and unbiased, with no carrier affiliations influencing the results. If a better plan would solve your problem, you'll find it there in a matter of seconds.

Frequently Asked Questions

How do I know if someone blocked me on iMessage?

There's no definitive in-app notification when you're blocked. The signs to look for: iMessages to that person consistently show "Not Delivered" (no delivery receipt), calls go straight to voicemail every time, and you never see read receipts even though the person is typically active. None of these alone confirms a block—but all three together is a strong signal.

Why does iMessage say "Not Delivered" to one person but works for everyone else?

When the failure is isolated to one contact, the most likely explanations are: they blocked you, they switched to Android without deregistering their number from iMessage, or their iMessage is temporarily off. Try sending them a regular SMS (hold the message bubble and select "Send as Text Message") to see if that goes through.

Can I use iMessage with just an email address and no phone number?

Yes. You can set iMessage to use your Apple Account email address instead of—or in addition to—your phone number. Go to Settings > Apps > Messages > Send & Receive and check your email address under "You can be reached by iMessage at." This is useful on iPad or Mac where you may not have a SIM.

Does iMessage work without Wi-Fi?

Yes—iMessage works over cellular data too. What it doesn't work without is any internet connection. If you have no Wi-Fi and no cellular data signal, iMessage won't send. iOS will fall back to SMS if cellular voice/SMS is available.

Why did my iMessages turn green all of a sudden?

The most common reasons: you lost your internet connection, iMessage got toggled off (check Settings > Apps > Messages), Apple's servers are experiencing an outage, or the person you're messaging switched to Android. Run through the Quick Fixes at the top of this guide first.

How long does iMessage activation take?

Usually a few minutes. Apple officially says it can take up to 24 hours in some cases, particularly when carrier verification involves an SMS that takes time to process. If you're past 24 hours and still seeing "Waiting for Activation," work through the activation steps above and contact your carrier if the issue persists.

Can I get iMessage on Android?

No. iMessage is exclusive to Apple devices—iPhone, iPad, Mac, and Apple Watch. There's no official Android app and no workaround that Apple supports. If you're switching to Android, use Apple's Deregister iMessage tool before you go, or your contacts' iMessages to your old number may never reach you.

What's the difference between iMessage and RCS?

iMessage is Apple's proprietary messaging system—blue bubbles, end-to-end encrypted, Apple devices only. RCS (Rich Communication Services) is a carrier-backed messaging standard that works across iPhone and Android—green bubbles on iPhone, supports read receipts and higher-quality media, but not end-to-end encrypted by default. iOS 18 added RCS support, so iPhone users now get a better cross-platform experience than old SMS—but it's still not iMessage.

Why are my iMessages out of order?

Out-of-order messages are almost always a time sync issue. Go to Settings > General > Date & Time and make sure Set Automatically is on. If the clock on your iPhone is even slightly off, message timestamps can get scrambled—especially noticeable when switching between Wi-Fi and cellular.

How do I deregister my phone number from iMessage after switching to Android?

Yes. You can set iMessage to use your Apple Account email address instead of—or in addition to—your phone number. Go to Settings > Apps > Messages > Send & Receive and check your email address under "You can be reached by iMessage at." This is useful on iPad or Mac where you may not have a SIM.

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