Agent transfer not working to australian number

Support Help
1

Hi - I’ve got my agent set up correctly where it can make calls to an australian number, though when the agent tries to transfer it to a real person (also an australian number) we are getting a busy error code.

examples:

2026-05-11 01:04:57.849 call_7e5f2ad3586df6f78d4d139879f error: Error transferring call, SIP status code: 486 SIP error category: user_busy Error: twirp error unknown: INVITE failed: sip status: 486: Busy Here
To troubleshoot, check out: Debug outbound connection issues - Retell AI

2

Hey @felix

The SIP 486 means the callee rejected/was busy — it’s a signal from the destination side, not a Retell config issue.

A SIP 486 Busy Here means the callee (the Australian person you’re transferring to) rejected the call or their line was actually busy. 486 = “Callee rejected the call” — it may be retried later.

Thank You