[(2) ]() If the issue persists, you may want to share specific call IDs with Retell support for detailed analysis, as they can review the exact cost breakdown for individual calls [(1) ]() .

### Answer Based on the available sources, there are a few potential reasons for the cost increase you're experiencing: Post-Transfer Call Time One documented reason for higher-than-expected costs is that you may be charged for the entire call duration, including time after a transfer [(1) ]() . If your agent transfers calls, you're billed for the full telephony time, not just the AI interaction time . Telephony Provider Differences The telephony costs can vary significantly depending on your provider [(2) ]() . For example, Telnyx charges approximately $0.06/min for telephony, which is 4 times higher than Twilio's rate of $0.015/min . If your telephony provider changed or if routing changed between February and March, this could explain the cost difference. Base Pricing Structure Retell AI's standard pricing is $0.07-$0.08 per minute for AI Voice Agents [(3) ]() [(4) ]() [(5) ]() , plus telephony charges (approximately $0.015/min with Twilio or $0.06/min with Telnyx) [(2) ]() , plus LLM processing costs ($0.006-$0.06/min depending on model choice) [(5) ]() . Next Steps To investigate further, I recommend: 1. Check your call details to see if transfers are extending call duration 2. Verify which telephony provider is being used for your calls 3. Review the detailed pricing breakdown at [)

​ To learn more, see the sources I considered: [[1] My cost per minute says .089, but I'm being charge at .1648/ minute](https://community.retellai.com/t/my-cost-per-minute-says-089-but-im-being-charge-at-1648-minute/739) [[2] Agent calls on webapp is fast but when it does outbound/inbound calls, the latency is so high (3-4s)](https://discord.com/channels/1186424376300679209/1428525820841824336) [[3] ](https://www.retellai.com/resources/voice-ai-platform-pricing-comparison-2025) [[4] ](https://www.retellai.com/resources/inbound-vs-outbound-callers-pricing-comparison-2025) [[5] 9 Top Yellow.ai Alternatives in 2026: Enterprise Comparison of Architecture, Pricing & Scalability | Retell AI](https://www.retellai.com/blog/yellow-ai-alternatives) ​

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

### Answer You're absolutely correct. When using Elastic SIP Trunking or the Dial to SIP URI method, Retell AI doesn't handle your telephony provider directly, so telephony costs shouldn't impact what Retell charges you [(1) ]() [(2) ]() . What Retell AI charges you for: Retell AI's base platform cost is $0.07-$0.08 per minute for AI Voice Agents [(3) ]() [(4) ]() . This covers: - Real-time speech recognition and synthesis - LLM processing - Post-call analytics and summaries - The AI conversation engine itself [(3) ]() What you pay your telephony provider separately: When using SIP Trunking, you manage telephony independently through your own provider (Twilio, Telnyx, Vonage, etc.) [(1) ]() [(2) ]() . Those costs are billed directly by your telephony provider, not through Retell [(1) ]() . Why your Retell costs might have increased: Since telephony isn't the issue, the cost increase from $0.15 to $0.21 per minute likely stems from: 1. LLM usage changes - If your agent's conversations became longer or more complex, LLM processing costs increase 2. Voice model selection - ElevenLabs voices cost $0.07/min while OpenAI/Deepgram voices cost $0.08/min [(3) ]() 3. Call duration - You're charged for the entire ca

ll duration, including any time after transfers [(1) ]() Next step: Check your call logs in the Retell dashboard to see the detailed cost breakdown per call. This will show exactly which components (voice engine, LLM processing, etc.) are driving the higher costs.

​ To learn more, see the sources I considered: [[1] Custom Telephony Overview](https://docs.retellai.com/deploy/custom-telephony) [[2] AI in SIP Calling & Telephony Solutions | Retell AI](https://www.retellai.com/blog/integrating-ai-with-sip-trunking-and-modern-telephony) [[3] ](https://www.retellai.com/resources/voice-ai-platform-pricing-comparison-2025) [[4] ](https://www.retellai.com/resources/inbound-vs-outbound-callers-pricing-comparison-2025) ​

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