# Questions to Ask an AI Voice Agent Vendor Before You Sign Ask about the full cost at your volume, concurrency limits, which model and voice providers the vendor uses, data retention, compliance documents, human handoff and how you leave. Get every answer in writing. Updated 2026-10-29. Also on the [web page](https://voiceagents.fyi/guides/questions-to-ask-an-ai-voice-agent-vendor). Use these questions in your vendor calls. Send them in writing too. Compare the answers side by side. A vendor that cannot answer a question clearly is giving you an answer. ## Cost 1. What is the total cost per minute at our volume? List every part: platform, model, speech-to-text, text-to-speech and telephony. 2. Which costs are passed through at cost, and which have a markup? 3. What monthly fees apply outside the per-minute rate? Ask about concurrency, phone numbers, knowledge bases, transfers and add-ons. 4. Is there a minimum monthly or annual commitment? 5. How do you bill partial minutes and transferred calls? 6. How much notice do you give before a price change? Why it matters: public pricing pages list many separate fees. On 2026-10-29, Retell AI listed $8 per month for each extra concurrent call. Bland AI listed $0.05 per transfer minute on its Start plan. Vapi listed $10 per extra line per month. ## Capacity and reliability 7. How many calls can we run at the same time on this plan? 8. What happens to a call when we pass that limit? 9. What uptime do you commit to in the contract? What is the credit if you miss it? 10. What is your support response time for an outage? Why it matters: limits differ by plan. Vapi listed a 99% uptime SLA on its Pro plan and 99.9% on Premier. Bland AI listed a 99.9% uptime SLA on all three plans. ## Models and voice 11. Which LLM, speech-to-text and text-to-speech providers do you use? 12. Can we choose or change the model and the voice? 13. Can we bring our own model or carrier account? 14. How do you test the agent after a model update? 15. What latency do you measure from the end of the caller's speech to the start of the reply? Ask for real call data, not a demo. ## Data and security 16. Where do you store recordings and transcripts? For how long? 17. Can we set the retention period, or turn recording off? 18. Do you use our call data to train models? 19. Who are your sub-processors? 20. Can we get a current SOC 2 report? 21. Will you sign a BAA? Is there an extra fee? 22. Will you sign a data processing agreement under GDPR Article 28? 23. At the end of the contract, do you delete or return our data? Why it matters: a HIPAA business associate contract must require the vendor to return or destroy health information at termination, where feasible (45 CFR 164.504(e)). GDPR Article 28 sets a similar rule for processors. Vapi listed its HIPAA add-on at $2,000 a month on 2026-10-29. ## Calls and handoff 24. How does the agent hand a call to a human? Is it a warm or a cold transfer? 25. Does the human see a summary of the call? 26. What happens when the agent does not know the answer? 27. How does the agent tell callers that it is an AI? ## Outbound calls 28. How do you help us get and record consent before you call? 29. How do you handle opt-out requests? Why it matters: the FCC ruled in February 2024 that AI-generated voices are an "artificial or prerecorded voice" under the TCPA. Such calls need the prior express consent of the called party, absent an emergency purpose or exemption (FCC 24-17). ## Exit 30. How do we export our agents, prompts, call logs and recordings? 31. What is the notice period to cancel? 32. Do our phone numbers move with us when we leave? ## How to use the answers - Put the answers in a table, one column per vendor. - Mark every answer that is not in writing. - Ask for the important answers in the order form or contract. Prices and terms change. Check each vendor page and contract before you sign. ## Sources - [Vapi, Pricing (fetched 2026-10-29)](https://vapi.ai/pricing) - [Retell AI, Pricing (fetched 2026-10-29)](https://www.retellai.com/pricing) - [Bland AI, Pricing (fetched 2026-10-29)](https://www.bland.ai/pricing) - [GDPR Article 28, Processor (gdpr-info.eu) (fetched 2026-10-29)](https://gdpr-info.eu/art-28-gdpr/) - [eCFR, 45 CFR 164.504, Uses and disclosures: organizational requirements (fetched 2026-10-29)](https://www.ecfr.gov/current/title-45/subtitle-A/subchapter-C/part-164/subpart-E/section-164.504) - [FCC, Declaratory Ruling FCC 24-17, CG Docket No. 23-362 (fetched 2026-10-29)](https://docs.fcc.gov/public/attachments/FCC-24-17A1.pdf) ## Questions ### Should the answers be in the contract? Yes, for anything that matters to you. A sales call or a pricing page can change. A signed contract or order form is what you can enforce. ### What is the most common surprise on the first bill? Fees outside the per-minute rate. Public pricing pages list separate fees for concurrency, phone numbers, transfers, add-ons and compliance plans. ### Can I ask a vendor which sub-processors it uses? Yes. Under GDPR Article 28, a processor needs the controller's written authorisation before it engages another processor. Ask for the current sub-processor list.