Questions to Ask a Voice AI Vendor Before You Sign

Before you sign with a voice AI vendor, get written answers in seven areas: the full per-minute price, response latency, languages, compliance, integrations, onboarding and contract exit terms. Vendors quote the cheapest layer of the price first, so the first question is always "what is the total cost per connected minute at my volume?"

This checklist is built for a request for proposal (RFP). Each question has a reason and a description of a good answer. Where we show vendor facts, they come from the vendor's own pages, checked on 15 November 2026. For Topcalls, every answer comes from our pricing page, our docs and our legal pages. You can score us on the same sheet.

Key Takeaways

• Ask for the total cost per minute, not the platform fee, because some vendors bill hosting, models and telephony as separate lines.
• Ask for latency measured on your own calls, at the median and at the slow end, not a marketing figure.
• Ask who owns consent and opt-outs. Topcalls keeps no do-not-call list, so the customer owns both.
• Ask for the recording retention period in writing. Retell keeps data until you change it, and Vapi's window runs from 14 to 180 days by plan.

• Ask what happens to your data when you leave, with a deletion deadline in the contract.

What questions should I ask a voice AI vendor before signing a contract?

Ask what you will pay at your volume, how fast it answers, which languages work, who owns compliance, what it connects to, how onboarding runs and how you leave. Seven areas cover most of what goes wrong. Put each question on a scoring sheet, send the same sheet to every vendor and compare the written answers side by side.

The rest of this post goes area by area. For each question we say why it matters and what a good answer looks like. A weak answer is vague ("it depends", "contact sales") with no number, no date or no document behind it. Score weak answers low even from a vendor you like.

What should you ask about pricing?

Ask for the total price per connected minute, including telephony, the language model, the voice and any platform fee, plus every minimum, setup fee and overage rate. Compare vendors on that total at your volume, not on the headline rate. A low platform rate often sits on top of costs that are billed separately.

Real examples show why. Vapi's pricing page lists $0.05 per minute for Vapi hosting, with models passed through at cost, so the model and voice come on top. Call Setter AI's pricing page lists a $497 monthly plan with 1,000 minutes, a $997 one-time setup fee and a $0.55 per minute overage rate. Neither is hiding anything. But you can't compare either with a flat rate until you've worked an example at your own volume.

• Per-minute total. Good answer: one number at your call volume, with each layer named (platform, telephony, language model, voice, recording).
• Minimums and bundles. Good answer: "none", or the exact monthly minimum and what happens to unused minutes.
• Setup and seat fees. Good answer: a list with amounts, or "none" in writing.
• Overage and concurrency. Good answer: the rate past the included volume and the price of extra simultaneous calls.

Topcalls answers it this way: AI calls start from $0.25 a minute depending on the country you call, billed by the second. The price covers the AI voice model, call recording, transcription and analytics, and the phone line is set by the country zone. There are no seat fees for AI calling, no setup fees for self-serve AI calling, no minute bundles and no separate transcription bill. See AI calling cost per minute for the breakdown, and run your numbers in the ROI calculator.

How fast should a voice AI agent respond?

Ask for end-to-end response time measured on real calls: the pause between the caller finishing a sentence and the agent starting to answer, at the median and at the 95th percentile. A good agent answers inside a normal conversational beat. The slow tail matters most, because callers hang up on long silences.

Treat every latency figure as a claim, and test it. Ask the vendor to run a pilot on your script and to share the timing from your own call logs. Also ask what happens when the vendor's language model provider is slow: a fallback model, a retry or a filler phrase. And ask whether the figure includes the phone network or only the vendor's servers.

• Median and slow tail. Good answer: two numbers, measured on live calls, with the date.
• Interruption handling. Good answer: a demo where you cut the agent off mid-sentence and it stops.
• Provider failure. Good answer: a named fallback and what the caller hears when it triggers.

Which languages does the voice AI really support?

Ask for the list of languages and dialects, and for the speech recognition and voice quality in each one, not only the count. A count of supported languages hides the fact that some voices are far better than others. Ask for sample calls in the languages you actually need.

For Topcalls, agents call in up to 78 languages. How many you get depends on the transcription and voice models you choose. That is a ceiling, not a default, and any vendor's headline count deserves the same question. The test is simple: have a native speaker listen to a recorded call in each language you plan to use, and score the accent, the pacing and the handling of names.

What compliance questions should you ask a voice AI vendor?

Ask who owns consent, opt-outs and do-not-call checks, how the agent discloses that it is an AI, whether calls are recorded, where data is stored and who the sub-processors are. Then ask for the data processing agreement (DPA). Most compliance failures start with a vendor assuming the customer handles something the customer assumed the vendor handled.

• Consent and opt-outs. Good answer: a clear split of duties. On Topcalls, the customer owns consent and opt-outs. Topcalls keeps no do-not-call list, and it controls dispatch hours, time zone and retries per campaign.
• AI disclosure. Good answer: a configurable opening line and a statement of which laws it was built for. See our guide to AI disclosure laws.
• Recording. Good answer: recording is configurable, and the vendor says who is responsible for notice and consent. See recording consent by state.
• Data location and sub-processors. Good answer: a named region and a current sub-processor list.
• DPA. Good answer: a signable document, not a promise. Topcalls publishes its DPA.

For the legal basis in Europe, read our guide to GDPR and AI outbound calling and the TCPA guide for the United States. This is general information, not legal advice.

How long does the vendor keep call recordings?

Ask for the default retention period for recordings and transcripts, the range you can set, who can change it and how fast deletion runs after the period ends. Vendors differ widely. Retell's default is no automatic deletion, Vapi's window depends on your plan, and Bland and Topcalls publish no default number.

That is why the answer has to be in writing. GDPR's storage limitation principle in Article 5(1)(e) says personal data may be kept only as long as the purpose needs. Our full comparison is in how long voice AI vendors keep call recordings. Good answer: a number, a setting you can change, and a deletion deadline in the contract. For Topcalls, ask us for the period for your account.

What should you ask about integrations?

Ask how the agent gets lead data in and sends results out, and ask to see it work with your system, not a logo wall. A catalog count tells you little. What matters is whether call outcomes reach your CRM in a form your team can act on.

On Topcalls, each finished call sends a webhook with the transcript, recording link, summary, extracted answers and your own metadata. Agents can also call your tools during a call to book an appointment or update a record. The integrations catalog lists 764+ tools, and we haven't tested every pair, so ask for a live test with yours. See our integrations page.

• Lead data in. Good answer: CSV import, API and your CRM, with custom fields the agent can see.
• Results out. Good answer: a payload sample with outcome, summary and structured fields.
• Mid-call actions. Good answer: a demo of the agent booking into a real calendar.

How does onboarding work, and how long until we are live?

Ask who builds the first agent, how long go-live takes, what you must provide and what the support response time is. A vendor that hands you a blank prompt box and a documentation link has a different cost from one that configures the agent with you, even at the same per-minute price.

On Topcalls, first campaigns are usually live within 2 weeks, set up with the Topcalls team, per our FAQ. Our advice for any vendor is to start with 10 to 20 leads and read the transcripts before you scale. Good answer: a named contact, a written timeline and a pilot plan with a pass mark you agree on first.

What contract terms should you check?

Check the term length, the notice period, auto-renewal, price change rights, what happens to your data on exit and whether you can export recordings and transcripts. Exit terms matter more than entry terms, because switching vendors is the moment you find out what you actually agreed to.

• Term and renewal. Good answer: monthly or a short term, with the renewal date in the order form.
• Price changes. Good answer: notice period and a cap, or a price lock for the term.
• Data export. Good answer: a self-serve export of recordings and transcripts, in standard formats.
• Deletion on exit. Good answer: a deadline. Topcalls' DPA says you choose delete or return, and it deletes within 30 days after you ask, or within 60 days after the end if you choose neither.
• Liability and uptime. Good answer: a written uptime target and what happens when it's missed.

How should you score the answers?

Give each area a weight that matches your risk, score every answer from 0 to 3 and write down the evidence next to the score. A 3 needs a document or a live demo. A 1 is a verbal promise. Run a paid pilot on your own leads before you sign a long term.

A simple weighting for outbound sales teams: pricing 25 percent, compliance 25 percent, latency and voice quality 20 percent, integrations 15 percent, contract and exit 15 percent. Change it if you call a regulated industry. Then ask each finalist to book the same ten test calls and compare the transcripts.

When you're ready to score Topcalls on your sheet, the AI voice agents page shows the call flow and the lead qualification solution shows a first campaign. Book a strategy call and bring the sheet.