🇻🇳 SMS Sending Problem During Vietnam Travel
This is a real case study from a customer who has consistently used NeoKOSIM's Vietnam eSIM for multiple trips to Vietnam.
After arriving in Vietnam, the customer tried to send a text message to a friend but encountered a sending failure. Voice calls and data worked perfectly, and messaging through iMessage was also functioning normally. However, only regular SMS messages couldn't be sent.
📱 Step-by-Step Solution
If you're experiencing this issue, please follow these steps in order:
Step 1: Check iOS Version
Please verify that your iOS is up to date.
- Example: iOS 18.5 or latest version
- Check via Settings > General > Software Update
Step 2: Verify Message Settings
Check your iPhone's message-related settings.
- Go to Settings > Messages
- Ensure the following options are enabled (ON):
- iMessage
- Send as SMS
- MMS Messaging
Step 3: Reset Network Settings (Key Solution)
This is the most effective solution.
- Settings > General > Transfer or Reset iPhone > Reset Network Settings
- This procedure resolves most issues.
🔧 Problem Root Cause and Solution Process
Why Does This Problem Occur?
For SMS sending to work properly, the SMSC (Short Message Service Center) number must be correct. If this number is missing or incorrectly configured, you can receive SMS messages but cannot send them.
How to Check SMSC Number
Example SMSC numbers for Vietnam carriers:
- Vinaphone SMSC Default Number: +8491020005
Verification Method:
- Open the dial pad and enter the following command
*#5005*7672#- Press the call button to check the currently configured SMSC number
💡 Additional Tips
- After resetting network settings, you'll need to re-enter Wi-Fi passwords
- If the problem persists, contact us for additional support
- It's recommended to test your eSIM settings before traveling
We hope this method helps you resolve SMS sending issues during your Vietnam trip. Have a safe and enjoyable journey to Vietnam! 🌴
