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READ THIS BEFORE MOVING YOUR SIM / eSIM

 

SMS Setup & Troubleshooting Guide
For Switching from Android/iOS to De-Googled, Minimal, & Feature Phones

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This guide is designed to be used as a setup checklist before switching from an iPhone or Android smartphone to a De-Googled phone, minimal phone, feature phone, or custom ROM device.

 

⚠️ READ THIS FIRST ⚠️

 

Complete ALL setup steps in Part 1 in order, BEFORE REMOVING YOUR SIM / eSIM.
 
YOU WILL LIKELY EXPERIENCE DISRUPTIONS WITH SOME GROUP MESSAGES 

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This dramatically reduces broken texts, missing group messages, and delivery failures.​ Group messages may prove the most tricky and give you the most problems in the short term, but the SLEKE. team and community is here to help you through it! 

 

If you've already switched phones and are experiencing problems, the same steps still apply, but may take longer or require carrier help. If this is you, skip to Part 2: Troubleshooting.

 

 

How to Use This Guide

 

This is a procedure to move your phone number between messaging systems.

 

If you have NOT moved your SIM from your Android/iOS device yet: start at Part 1 and proceed in order.

 

If you already moved your SIM from your Android/iOS device: Start at Part 2, but expect delays and possible carrier intervention.

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Helpful Background (so you can sound smart at dinner parties)

 

Modern phones use three incompatible messaging systems:

 

SMS/MMS: Old, universal, works on all phones

iMessage: Apple-only, sticky, group chats persist indefinitely

RCS: Google + carriers, now default on Android and iPhone

 

When you move your SIM without deregistering first, other phones keep trying to reach you using iMessage or RCS, which your new phone cannot receive. In other words, messages get stuck on the wrong "track." This guide forces them onto the SMS/MMS track. 

 

The solution: Deregister from RCS and iMessage BEFORE switching phones. Just like cancelling a subscription, you need to opt out while you still have access.

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PART 1:
SETUP GUIDE 
(Do this before switching your SIM/eSIM between devices)

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Follow these steps in order while your SIM / eSIM is still in your smartphone. 

Do not skip steps, even if they seem unnecessary.

 

For eSIM users: Save your carrier's eSIM activation QR code or instructions before deactivating your smartphone. Some carriers allow you to have the same eSIM profile on multiple devices temporarily. If yours does, you could activate the eSIM on your basic phone BEFORE deactivating it on your smartphone, allowing you to test messaging before fully committing to the switch.

 

STEP 1 (for iPhone): Disable iMessage, FaceTime, & RCS

Do this AT LEAST 3 days before switching phones. 

Apple's systems can take up to 3 days to fully deregister your number.

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  1. Disable iMessage

    1. With your SIM / eSIM still in your iPhone, open Settings

    2. Open Settings > Apps > Messages

    3. Toggle iMessage OFF

    4. Tap Send & Receive

    5. Verify your phone number is deselected

    6. Visit https://selfsolve.apple.com/deregister-imessage/

    7. Enter your phone number

    8. Complete the verification process

  2. Disable FaceTime (Multiple users report messages didn't work until FaceTime was also disabled. Don't skip this step.)

    1. Open Settings > Apps > FaceTime

    2. Toggle FaceTime OFF

  3. Disable RCS on iPhone (iOS 18+) (Newer iPhones now use RCS by default. You cannot turn off RCS without the SIM card in the iPhone. This must be done before removing your SIM.)

    1. Open Settings > Apps > Messages > RCS Messaging

    2. Toggle RCS Messaging OFF

    3. Confirm iMessage is OFF

  5. Wait at least 72 Hours before removing your eSIM/SIM

    1. Wait at least 72 hours (3 days) before switching phones. This gives the messaging systems time to propagate your deregistration across all servers.

    2. During this period you should see your message bubbles turn green. You should still receive your messages as normal on your iPhone.

    3. ​Waiting 3-Days before removing your eSIM/SIM from your iPhone ensures Apple’s servers fully deregister your phone number from their system, preventing messages from being lost or sent to your old device. This waiting period prevents "iMessage limbo" where messages fail to deliver as SMS/MMS.

 

STEP 1 (for Android): Disable RCS 

Do this AS EARLY AS POSSIBLE before switching phones. 

Android systems can take up to 30 days to fully deregister your number.

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RCS deactivation takes up to 30 days to fully complete. If you use online deregistration, you'll be immediately removed from all RCS group chats. On-Device based deactivation gives you a 30-day grace period. 

The 30-day deactivation period resets each time you deregister RCS online. Do not do this.
 

  1. On-Device (Disable RCS in Google Messages)

    1. With your SIM card still in your Android phone, open Google Messages

    2. Tap Menu (⋮) > Settings > Chat features / RCS Chats

    3. Toggle RCS OFF

    4. Confirm when prompted (you'll be removed from RCS group chats after 30 days)

  2. Online Deregistration (Your only option if you no longer have your original device)

    1. Visit https://messages.google.com/disable-chat

    2. Follow the 'without device' instructions

    3. Complete verification

 

STEP 2: Prepare for the SIM Swap

  1. If using a Physical SIM Card

    1. Power down BOTH phones completely (this ensures clean network handoffs and prevents conflicts.)

    2. Remove SIM card from your smartphone

    3. Insert SIM card into your De-Googled phone, minimal phone, feature phone, or custom ROM device

    4. Power on your new phone

  2. If using an eSIM (Unlike physical SIM swaps, you don't need to power down both devices for eSIM transfers. Wait for complete deactivation on the first device before activating on the second)

    1. Log into your carrier's website or app (Each carrier's process may vary slightly and can change over time. If these instructions don't match your carrier's current interface, contact customer support for the most up-to-date eSIM transfer procedure.)

    2. Navigate to your device management or eSIM settings

      1. AT&T:

        1. Visit myAT&T website or app

        2. Navigate to 'My devices' or 'Device settings'

        3. Select the device with active eSIM

        4. Choose 'Update device' or 'Replace device'

        5. Follow prompts to transfer eSIM to new device

      2. Verizon:

        1. Open My Verizon app or visit Verizon.com

        2. Go to 'Devices' section

        3. Select 'Activate or switch device'

        4. Choose the line with eSIM

        5. Select new device and follow activation steps

      3. T-Mobile:

        1. Open T-Mobile app or visit T-Mobile.com

        2. Navigate to 'My Account' > 'Phone'

        3. Select 'Change SIM'

        4. Choose 'Use eSIM' option

        5. Scan QR code or enter activation code on new device

    3. Deactivate the eSIM on your smartphone

    4. Wait a few minutes for deactivation to process

    5. Activate the eSIM on your basic phone following your carrier's instructions

 

STEP 3: Configure Your New Phone for Individual & Group SMS/MMS

  1. Enable Mobile Data (MMS [including group texts] requires mobile data to work, even if you don't use data for anything else.)

    1. Open Settings

    2. Find Network/Connections settings

    3. Toggle Mobile Data ON

 

  1. Configure Group Messaging Settings (This is the most important setting for group texts)

    1. Open your messaging app

    2. Open Settings > Advanced > MMS / Group Messaging 

    3. Enable 'Send a single MMS to all recipients' (NOT 'Send individual SMS messages')

    4. Verify Group messaging is enabled

    5. Verify MMS is enabled

 

STEP 4: 'Re-Train' Your Messaging

Messages may fail occasionally for the first few days while other phones 're-learn' that your number only supports SMS/MMS. This is normal.

 

  1. Send & Receive a test SMS to/from an Android user

  2. Send & Receive a test SMS to/from an iPhone user

  3. 'Dump Text' your Group Messages (Most issues will occur here. See ISSUE 2 in Part 2: Troubleshooting

    1. Do a lot of quick succession messaging in a 30-Minute period with 3+ members of the group chat. This retrains the servers (especially on iPhones) to send SMS/MMS to your number instead of RCS or iMessage after the session ends.

ddddd​​

STEP 5: Inform Your Contacts

  1. Let your frequent contacts know:

    1. You've switched to a different phone

    2. Old group chats may need to be recreated

    3. Messages should go through, but may take a few days to stabilize

 

STEP 6: Wait the Full 30-Day Period

  1. After disabling RCS, you must wait up to 30 days for the deactivation to fully complete

    1. Days 1-7: Messages may be spotty as systems transition

    2. Days 7-21: Most messages should work, but some contacts may still have issues

    3. Days 21-30: Nearly all messages should work correctly

    4. Day 29-30: Many users report complete resolution

 

Be patient! Don't conclude you have a problem until after the 30-day period is complete.



PART 2:
TROUBLESHOOTING 
(Don’t Panic)

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Use this section if you've already switched phones and are experiencing problems, or if you completed the setup steps but still have issues after 30 days.

 

Understanding Common Issues

 

  1. Messages Go to Individual Texts Instead of Group

    1. Your device is sending SMS instead of MMS. Check your group messaging settings (see Step 4 in Setup Guide).​

  2. MMS Timeout or Temporary Blocking

    1. Some carriers temporarily block MMS after high volume in a short period. This typically resolves in 10-30 minutes. Reprovisioning your line can prevent future occurrences.

  3. Why Some Groups Work and Others Don't

    1. Messages want to travel along the track they're accustomed to. New group combinations usually work fine, but recreating an old group with the same members often fails because the messaging system remembers the old protocol. The only solution is complete deletion and fresh start.

  4. eSIM-Specific Issues: Missing MMS/Media Messages

    1. Some eSIM users report that while regular SMS texts work fine, they occasionally miss MMS messages containing photos, videos, or group texts. This appears to be related to how some carriers provision MMS data access for eSIM devices.

    2. Possible solutions:

      1. Verify mobile data is enabled (absolutely required for MMS)

      2. Check your APN (Access Point Name) settings match your carrier's requirements

      3. Contact carrier to verify MMS is properly provisioned for your eSIM

      4. Request carrier to refresh your network profile

      5. Try the eSIM deactivation/reactivation cycle (see eSIM troubleshooting above.

      6. Technical note: MMS messages use cellular data, not SMS channels. Even if SMS works perfectly, MMS can fail if the data connection or APN settings aren't configured correctly for your eSIM. This is more common with eSIM than physical SIM because some carriers have different provisioning paths for each.

 

ISSUE 1: Already Switched Without Disabling iMessage/RCS

If you've already removed your SIM card, you'll need to temporarily put it back:

 

  • For iPhone Users with SIM:

    • Power down both phones

    • Move SIM back to iPhone

    • Power on iPhone

    • Open Settings > Apps > Messages > Turn OFF iMessage

    • Open Settings > Apps > FaceTime > Turn OFF FaceTime

    • Open to Settings > Apps > Messages > RCS Messaging > Turn OFF

    • Visit https://selfsolve.apple.com/deregister-imessage/ and complete online deregistration

    • Power down iPhone, move SIM back to the new phone and power it on

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  • For iPhone Users with eSIM (If you've already transferred your eSIM to your basic phone, you'll need to temporarily transfer it back to your iPhone):

    • Log into your carrier's website or app

    • Deactivate eSIM on your new phone

    • Wait 2-5 minutes for the deactivation to fully process

    • Reactivate eSIM on your iPhone (follow your carrier's activation process)

    • Wait for iPhone to fully connect to network

    • Go to Settings > Apps > Messages > Turn OFF iMessage

    • Go to Settings > Apps > FaceTime > Turn OFF FaceTime

    • Go to Settings > Apps > Messages > RCS Messaging > Turn OFF

    • Also visit https://selfsolve.apple.com/deregister-imessage/ and complete online deregistration

    • Wait at least 24 hours (ideally 48-72 hours) for full deregistration

    • Log back into your carrier account and deactivate eSIM on iPhone

    • Reactivate eSIM on your basic phone

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  • For Android Users without Original Phone (If you don't have access to your old phone, use remote deactivation): 

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  • For Android Users with SIM (If you've already transferred your SIM to your basic phone, you'll need to temporarily transfer it back to your Android):

    • Power down both phones

    • Move SIM back to Android

    • Power on Android

    • Wait for Android to fully connect to network

    • Follow Step 1 for Android in PART 1: SETUP GUIDE\​​

 

  • For Android Users with eSIM (If you've already transferred your eSIM to your basic phone, you'll need to temporarily transfer it back to your Android):

    • Log into your carrier's website or app

    • Deactivate eSIM on your new phone

    • Wait 2-5 minutes for the deactivation to fully process

    • Reactivate eSIM on your Android (follow your carrier's activation process)

    • Wait for Android to fully connect to network

    • Follow Step 1 for Android in PART 1: SETUP GUIDE

 

ISSUE 2: Group Texts Not Working

Once a group chat is established as fully iMessage or RCS, it stays that way forever. Old group chats cannot be converted, often, they must be recreated

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  • Solution 1: Verify Your Phone Settings

    • Make sure your group messaging is configured correctly (see STEP 4 in Part 1: Setup Guide).

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  • Solution 2: Spam or "Dump Text" the Group Chat

    • Have 3 or more members of the group chat do a lot of quick succession messaging within a 30 minute period.

      • This 're-educates' other phones that your number only supports SMS/MMS.

      • This can take a few hours to a few days to work.

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  • Solution 3: Phone Number-Only Contacts

    • Ask all group members to remove any other contact information besides your phone number from your contact card in their phone (this includes e-mail).

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  • Solution 4: Clean Slate Group Chat

    • Ask all group members to:

      • Remove group names and group photos

      • Send and receive a test message in the group

      • If the above steps do not work, backup then delete all chat history 

      • Send and receive a test message in the group

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  • Solution 5: Create New Group Chats

    • Ask someone to create a brand new group chat

    • Add all the same members

    • If that doesn't work, try adding or removing one person to create a different combination

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ISSUE 3: Still Not Working After 30+ Days

If you completed all setup steps and waited 30+ days, the problem is likely carrier-related.

 

  • Solution 1: Phone Number-Only Contacts

    • Ask the other person to remove all contact information besides your phone number from your contact card in their phone (this includes e-mail).

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  • Solution 2: Request Carrier Reprovisioning

    • Contact your carrier and request:

    • 'Reprovision' or 'refresh' your phone line

    • Confirm SMS and MMS are enabled

    • Remove any RCS or iMessage flags from your account

    • Update the text profile on your account

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  • Solution 3: Physical SIM / eSIM Swap (Carrier Reporovisioning Trick)

    • On some carriers, switching from a physical SIM to eSIM (or vice versa) forces a full backend reprovision.

    • Often works immediately, but may be temporary and recur in 1-3 weeks

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  • Solution 4: MMS Blocking Toggle

    • Log into your carrier account online

    • Find 'Block picture and video messaging' setting

    • Toggle it ON, wait 1-2 minutes

    • Toggle it back OFF

    • Restart your phone

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  • Solution 5: Verizon-Specific Steps for SIM

    • If you're on Verizon, contact Tier 2 Technical Support and request:

    • Switch SIM to 'CDMA-less' status

    • Disable 'Enabled Address Book'

    • Disable 'Verizon Messaging'

    • Disable 'Video Calling'

    • Verify SIM isn't locked to another device

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  • Solution 6: Test with a New Number

    • To verify if the problem is provisioning-related:

    • Get a cheap temporary number (e.g., Tello $5 plan)

    • Test messaging with the new number

    • If it works immediately, your original number has provisioning issues

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  • Solution 7: Switch Carriers (Last Resort)

    • Multiple users report that switching carriers completely resolved persistent issues. 

    • Mint Mobile is frequently reported as problem carrier regarding this process

 

ISSUE 4: Additional Troubleshooting

Try these in order if standard solutions don't work:

 

  • Clear Messaging App Cache and Data (Many users report this fixes “Not sent, tap to try again” errors)

    • Open Settings > Apps > Messages > Storage

    • Tap Clear Cache 

    • Tap Clear Data (this deletes local message history)

    • Restart phone

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  • Check Messaging App Permissions

    • Verify your messaging app has:

      • Location permission (required by some apps)

      • Storage permission (for MMS attachments)

      • Phone and SMS permissions

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  • Reset Network Settings (Note: This erases Wi-Fi passwords, VPN settings, and cellular configurations)

    • iPhone: Settings > General > Transfer or Reset > Reset > Reset Network Settings

    • Android: Settings > General management > Reset > Reset network settings

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  • Switch Default Messaging App

    • If your phone has multiple messaging apps, try switching the default and then switching back. This can reset stuck configurations.

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  • Factory Reset (Last Resort)

    • Multiple users report factory resets resolved persistent messaging issues by clearing software glitches and forcing clean network connections.

    • Before factory resetting: 

      • Back up all data, contacts, and photos

      • Save all account passwords

      • Remove Google/Apple accounts from the device

 

ADDITIONAL RESOURCES

 

Fixing RCS and iMessage for Dumbphones! (Video)

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