The BlackBerry® MVS Client might not be installed on the BlackBerry device or registered with the BlackBerry® Mobile Voice System.

On the BlackBerry device, try performing the following actions:

• Verify that the BlackBerry MVS Client is installed. To view applications on the BlackBerry device, click Options > Advanced Options > Applications. Look for the BlackBerry MVS Client.
• Verify that the BlackBerry MVS Client is registered with the BlackBerry MVS. If the menu item does not appear on the BlackBerry device, or if the registration fails, see additional troubleshooting topics. If the registration process does not complete, wait for a short period of time and then try again.

The user might be roaming outside of the wireless service provider's network.

If the user is roaming outside of the wireless service provider's network, the BlackBerry device does not display correct caller IDs. After the user is no longer roaming, verify that the user sees the correct caller IDs.

The BlackBerry device might not be active.

Try performing the following actions:

• Verify that the phone is active. In the BlackBerry MVS web UI, on the User menu, click Phones. Beside the BlackBerry device, verify that the Phone On option is selected.
• Verify that the email address for the BlackBerry device is correct for the user's BlackBerry® Enterprise Server user account. In the BlackBerry MVS web UI, on the User menu, click User Profiles. Click the user account. In the Email Address field, verify the email address.
• Verify that the PIN for the BlackBerry device is correct for the user's BlackBerry Enterprise Server user account. In the BlackBerry MVS web UI, on the User menu, click Phones. Click the BlackBerry device. On the MVS tab, in the Device PIN field, verify the PIN.

The PSTN trunks or PBX might not be capable of sending a caller ID of up to 14 digits.

Try performing the following actions:

• Verify that the PSTN trunks (local, long distance, and international) are capable of sending a caller ID of up to 14 digits.
• Verify that the PBX is capable of sending a caller ID of up to 14 digits.

The caller ID might be configured as your organization's main listed number.

If the BlackBerry device displays your organization's main listed number, try performing the following actions:

• Verify that your organization's PBX is not sending your organization's main listed number as the caller ID.
• Verify that the local exchange carrier is not sending your organization's main listed number as the caller ID.