Symptoms
- Text message code never arrives
- Authenticator app codes don't match what the site expects
- Code arrives but after it has already expired
- Voice call for code doesn't come through
Likely causes
- CommonWeak cellular signal delaying or blocking the SMSVerification texts are sent like any other SMS and can be delayed by poor signal.
- CommonWrong phone number on file with the serviceIf the number was changed and not updated everywhere, codes go to the old number.
- PossibleAuthenticator app's clock out of syncTime-based codes fail if the phone's clock drifts from correct time.
- PossibleCarrier-side SMS filtering blocking short codesSome carriers or spam filters block certain short-code senders.
- Less commonDo Not Disturb or message blocking hiding the incoming textA blocked short code number would silently drop the message.
What to do
- Confirm you have signal and try requesting the code again after moving to a stronger signal area.
- Check that the phone number on file with the account is your current number.
- If using an authenticator app, confirm the phone's date and time are set to automatic, since code generation depends on accurate time.
- Try requesting a phone call instead of a text if that option is offered.
- Check your messaging app's spam or blocked folder for the code text.
- Use a backup verification method (backup codes, another trusted device, or email) if available while resolving SMS delivery.
When to call a pro
If codes never arrive across multiple attempts and your number is confirmed correct, contact your carrier to check for SMS short-code blocking, and the service's support for alternate verification.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.