Phone System · 1 min read
Error 21614: "To" Number Is Not a Valid Mobile Number
What this error means
Error 21614 means the destination number could not be validated as a mobile number that can receive SMS. The number may be a landline, invalid, formatted incorrectly, or a non-standard machine-to-machine (IoT) number.
Common causes
- The number is a landline.
- The number is missing digits or has the wrong country code.
- The number is not in E.164 format (for example
+15551234567). - The local prefix is wrong.
- The number belongs to an IoT or M2M service.
- Imported or manually entered contact data is incorrect.
How to fix it
- Open the contact and check the number.
- Confirm it belongs to a mobile phone. Ask the contact if you aren't sure.
- Verify the country code and format the number in E.164.
- Remove spaces and extra characters, then save the contact.
- If the number is a landline, call the contact instead or ask for a mobile number.
- Re-send the message.
Prevention
- Collect mobile numbers specifically on forms when you plan to text.
- Validate phone data before importing contacts.
- Route landline contacts to call or email steps in your workflows.