Check these first
Do not assume the cause from the symptom alone. First determine whether the issue affects the whole phone, one app, one connection, or one accessory. Work from low-impact checks toward recovery or repair.
- Determine whether ordinary SMS, verification codes, or both are missing
- Verify country code, leading zero, and the registered phone number
- Check spam, blocked senders, filtered tabs, and archived messages
Critical diagnosis for this symptom
Separate ordinary SMS from verification codes; check sender type, spam filters, dual SIM, and number changes.
Never share a verification code with another person.
Escalate with device, OS, error, and reproduction details when the issue persists after restart, controlled comparison, and update checks, or when physical damage, abnormal heat, account suspension, or carrier provisioning is suspected.
Narrow down the cause
| Scope of the issue | Where to check next |
|---|---|
| Only one app is affected | Check app permissions, updates, storage, cache, and reinstall options |
| The whole phone is affected | Check restart, system updates, free storage, and system settings |
| Other devices have the same issue | Check the network, service, charger, or accessory |
| The issue began after a drop or liquid exposure | Avoid repeated power or charging attempts and contact official support |
See the troubleshooting flow
Safe step-by-step process
Complete one step at a time and test after each change. Do not change several settings at once.
- 1Toggle Airplane mode for about ten seconds, restart the phone, and let it register with the network again.
- 2Ask another mobile phone to send a short SMS so you can test general reception.
- 3Review spam filtering, blocked senders, notification settings, and available message storage.
- 4On dual-SIM phones, confirm the registered number and active line. While abroad, check roaming and international-SMS conditions.
- 5If only a verification code is missing, do not repeatedly request it. Wait for the stated interval and use an official voice-call, authenticator, or recovery option.
- 6Ask the carrier to check SMS restrictions and line provisioning, and ask the sender to verify number format and service status.
Actions to avoid
- Sharing a verification code with another person
- Pressing resend repeatedly and triggering a temporary limit
- Guessing SIM PINs, recovery codes, or account passwords
Prevent the issue from returning
- Store backup authentication methods and recovery codes securely
- Update important accounts promptly when your phone number changes
Frequently asked questions
What if my screen looks different?
Menu names and locations vary by OS, manufacturer, model, region, and software version. Use the Settings search field and check the manufacturer guide for your exact model.
When should I stop troubleshooting?
Stop as soon as the issue is fixed. Change one setting at a time so you can identify what solved the problem and reverse it if necessary.
What should I do if the issue remains?
Record how to reproduce it, verify your backup, and contact the manufacturer, carrier, or app provider most closely related to the problem.