How to choose an AI voice agent vendor: 12 questions to ask before signing

The AI voice agent market is full of vendors who promise everything, explain little, and surprise-bill later. Here are the 12 questions to ask before signing. Track the response quality — that's your best differentiation signal.

Block 1 — business model#

• What's the per-minute cost above the subscription? (Should be under $0.50 to be viable.)
• Are there hidden costs on human transfers, follow-up SMS, or recordings? ('No' is the only good answer.)
• What happens if I exceed monthly quota? (Per-unit overage acceptable; cutting off calls is a deal-breaker.)
• Can I cancel in 1 click, end of current month? (Lock-in > 1 month = red flag for SMBs.)

Block 2 — technical quality#

• What's the average latency between the customer's last word and the agent's first? (Under 700ms required.)
• How does the agent handle barge-in (caller interruption)? (Vague answer = fail; numbers in ms = serious.)
• What share of calls are handled without human handover at your existing customers? (85-92% is credible; >95% is suspicious.)

Block 3 — compliance and data#

• Where are transcripts stored (EU, US, other)? Under which regulation?
• Did you sign a DPA (Data Processing Agreement)? (Required under GDPR.)
• What happens to customer data if I cancel? (Deletion within 30 days is standard.)

Block 4 — actual operation#

• Time-to-production on a typical case? (24-72h is credible; 'it depends' is a red flag.)
• Average support response time? (Specific in hours = serious; 'ASAP' = fail.)

The golden rule#

A vendor who hesitates, dodges, or answers 'it depends' to more than 3 of these 12 questions doesn't have technical command of their own product. A vendor answering with numbers + magnitudes on 10/12 is probably operational. First month VocazAI free to test our answers against your real flow.