Country whitelisting for call transfer
# ❓・bug-reportn
Nokts
02/26/2026, 5:46 PMHi Retell Support,
I'm based in Spain, and I want my agents to transfer calls to a Spanish number (+34). When the agent calls the tool, it fails, and taking a look at the log I see that apparently Spain is not within the allowed countries. However, as you can see, I made sure to select Spain on the allowed outbound countries. It seems to not be recognizing that.
Thank you for your attention.
https://cdn.discordapp.com/attachments/1476636428149719090/1476636428850172015/image.png?ex=69a1d857&is=69a086d7&hm=9592f7c4d72ccbcef14ddc3db4bb075a9cda2e90eb1344da6b2f4f2faf110807&
https://cdn.discordapp.com/attachments/1476636428149719090/1476636429407748148/image.png?ex=69a1d857&is=69a086d7&hm=43bcfcae08e01804f6e9d2d65223ddec5fab7b5d7034ce369340c36acc718f89&
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Shah - support @ Retell AI
02/26/2026, 6:28 PMHi @Nokts
Shah - support @ Retell AI
02/26/2026, 6:28 PMCan you send your org id
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Nokts
02/26/2026, 6:40 PMHi @User, this is the id: org_64A4GYSFvxDF873q
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Shah - support @ Retell AI
02/26/2026, 6:54 PMcan you provide a call id too
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Nokts
02/26/2026, 6:55 PMcall_74a62845bfa9323b2560abc84d8
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Shah - support @ Retell AI
02/26/2026, 6:56 PMOk i report this to the team
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Nokts
02/26/2026, 6:57 PMThank you Shah, looking forward to a solution
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Shah - support @ Retell AI
02/26/2026, 7:21 PMHi @Nokts you are using custom telephony, so the country whitelisting is managed by your provider, not by us.
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Nokts
02/26/2026, 7:24 PMThat's correct, but Telnyx, my provider, is already configured to allow Spain as a destination. Furthermore, we're switching to Retell from VAPI, where the call transfer to Spanish numbers worked just fine. Therefore, we can guarantee that this issue is on Retell's side and that's why we seek support.
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Omar Ashraf | Community Lead
02/26/2026, 7:31 PMHello @Nokts , in the images you sent the error is coming from your provider not us, if you check the error you will find it ends with D13
this is what D13 means in Telnyx docs
https://cdn.discordapp.com/attachments/1476636428149719090/1476662879024320534/image.png?ex=69a1f0f9&is=69a09f79&hm=9344d47db180c5a7ed87fda75421ef55098246aed3c40db176b6dc05628f2353&
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Nokts
02/26/2026, 7:35 PMThe outbound profile assigned to the SIP trunk has Spain whitelisted. It's also the same profile we were using with VAPI. If Telnyx was blocking the call, then we wouldn't have been able to transfer calls with VAPI.
https://cdn.discordapp.com/attachments/1476636428149719090/1476664098082131988/Screenshot_2026-02-26-20-33-13-40_ae33c6f1cf6771e633bcb779de95c7e0.jpg?ex=69a1f21c&is=69a0a09c&hm=98e171b417f84756b0a08fe2bfb16b7816e0e3c093c73e569c492c6faaec069b&
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Omar Ashraf | Community Lead
02/26/2026, 7:41 PMI understand you, but from the logs we tried to dial the number but your provider returned an error and this error D13 which is only associated with Telynx not us,
what you can do now download the PCAP file and send it to their support.
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Nokts
02/26/2026, 7:46 PMAlright, I'll reach out to Telnyx's support and hopefully they can figure it out. I'll report back when I receive a response.
Thank you for your help!
Nokts
02/26/2026, 8:30 PMI just tested a direct outbound call from Telnyx to a Spanish number using the same outbound voice profile assigned to my SIP trunk, and it went through successfully. This confirms Telnyx is not blocking the call. The 403/D13 is being generated somewhere in Retell's call transfer flow before or instead of reaching my Telnyx SIP trunk properly. Can you check how Retell routes transfer_call SIP INVITEs for custom SIP trunk connections? It may be going through a Retell intermediary that has its own country restrictions.
Nokts
02/26/2026, 8:37 PMThe following API call, which uses the same outbound profile where Spain is whitelisted, is able to make the call successfully.
https://cdn.discordapp.com/attachments/1476636428149719090/1476679625856782466/image.png?ex=69a20092&is=69a0af12&hm=6a6a3d490caa98dbd9dbb09f092a76318a24b035be691d3a7002f8fab9bd68af&
Nokts
02/26/2026, 8:49 PMHi @Omar Ashraf | Community Lead, just wanted to follow up — I found the fix. The issue was that the Transfer Call tool was set to SIP INVITE, which means Retell initiates the outbound call to the transfer destination through its own infrastructure. That's where the country restriction (USA, CAN only) was being applied, before it ever reached my Telnyx SIP trunk.
Switching the SIP Transfer Method to SIP REFER resolved the issue. With SIP REFER, Telnyx handles the transfer directly using my outbound voice profile, which has Spain whitelisted.
This might be worth noting in your docs or as a known issue — anyone using a custom SIP trunk with international transfer destinations will likely hit this same 403/D13 error if they're using SIP INVITE. Thanks for your help.