Overview
A Carrier Network Error (OCN) occurs when your mobile carrier does not send required call information to YouMail during call forwarding. Without OCN data, YouMail cannot determine who is calling or which inbox the call belongs to. This guide explains what OCN is, why the error happens, and how to resolve it so callers can leave messages successfully.
Key benefits / use cases
Restore voicemail functionality: Ensure callers can leave messages without errors
Fix activation issues: Resolve problems during YouMail setup or call forwarding
Improve call routing accuracy: Allow YouMail to correctly identify callers and inboxes
What is an OCN error?
An OCN (Original Call Number) error happens when your carrier fails to forward required call details to YouMail.
OCN information includes:
The number that was originally called
The number calling you
The time of the call
The location of the call
This information allows YouMail to recognize the caller and route the call to the correct voicemail inbox. When OCN data is missing, calls cannot properly connect to your voicemail.
How OCN errors affect voicemail
When an OCN error occurs, you may experience one or more of the following:
Callers hear an error message and cannot leave a voicemail
Callers are prompted to re-enter the number they dialed
Voicemail activation fails or behaves inconsistently
Important: OCN routing is controlled entirely by your carrier. YouMail cannot receive or generate OCN data without carrier support.
How to resolve a carrier network (OCN) error
Resolving an OCN error usually requires carrier involvement.
To fix an OCN error, follow these steps:
Contact your mobile carrier’s customer support.
Explain that conditional call forwarding is active but OCN information is not being passed correctly.
Ask the carrier to manually set up conditional call forwarding to your YouMail deposit number.
Confirm with the carrier that OCN data will be forwarded with all voicemail calls.
Important: Only your carrier can enable or correct OCN routing. This cannot be fixed directly within the YouMail app.
Note
Most OCN errors occur even when call forwarding appears active. Manual carrier setup is often required to fully resolve the issue.
Tip
If the first representative is unfamiliar with OCN or conditional call forwarding, request advanced or tier-two technical support.
Pro tip
Once the carrier confirms the fix, place a test call