### Answer --- I don't have specific documentation about caller ID digit truncation issues within Retell AI's sources. However, this type of issue typically relates to how phone numbers are formatted between your telephony provider and Retell. Phone numbers should be in E.164 format, which includes the country code prefixed with a plus sign (+) , followed by the number with no spaces or special characters (e.g.,

"+14157774444"

) . [(1) ]() A few things to check: - **Verify the number format on import**: When importing phone numbers into Retell, ensure they're in proper E.164 format with the full country code. - **Check your SIP trunk/telephony provider settings**: The issue may originate from how your phone system or SIP trunk is passing the caller ID to Retell. Review your origination settings in your SIP trunking provider. [(2) ]() - **Contact your telephony provider**: Since your phone system picks up the full number but Retell shows a missing digit, the issue may be in how the caller ID is being transmitted through the SIP trunk. Check the logs on your telephony provider's side. If the configuration appears correct on your end, you may want to reach out to Retell support with specific call IDs so they can investigate the SIP signaling. Check out these potentially useful sources: - [Custom Telephony Overview]() - [Debug outbound connection issues]() Would you like me to try providing a more general answer about caller ID handling?

​ To learn more, see the sources I considered: [[1] SIP Trunk Outbound Call - No SIP INVITE reaching my server](https://community.retellai.com/t/sip-trunk-outbound-call-no-sip-invite-reaching-my-server/760) [[2] Custom Telephony Overview](https://docs.retellai.com/deploy/custom-telephony) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.