A Checklist for Choosing a Voice AI Vendor for Financial Services
Score vendors on a real phone call, not a demo
Voice AI demos run over wifi with a scripted question. Your callers are on a phone line asking about their application. This voice AI vendor checklist is built around whether a vendor holds up under those conditions, and whether it meets the compliance bar a regulated call carries.
1. Speech pipeline latency
- Is it native speech-to-speech, or a cascaded speech-to-text then LLM then text-to-speech chain?
- Ask for a measured turn-taking latency on an actual PSTN call. Cascaded stacks add up to seconds; conversation stops feeling like conversation past a few hundred milliseconds.
2. Barge-in
- Can a caller talk over the agent and be understood mid-utterance, or does it finish its sentence first?
- How does it behave with background noise on the line?
3. Actions under your rules
- Can it call your systems — application status, product eligibility — and run your rules, or only answer from an FAQ set?
- Are tool calls schema-validated so a malformed action can't execute?
4. The warm handoff
- Does escalation transfer the live call with the transcript and structured data preloaded on the human's screen, or is it a cold transfer into a fresh queue?
- Can you set hard escalation rules — anything that could constitute an adverse action goes to a human?
5. Compliance
- A recording-consent disclosure and a stored consent record, not just the disclosure playing.
- A plain AI disclosure near the start of the call.
- The model is not the final decision-maker on anything that could be an adverse action.
- Retention terms for audio and transcripts, and awareness of all-party-consent states.
6. Telephony and data handling
- Does it bridge to your existing phone number, or force a new one? What's the CPaaS dependency?
- Where do audio and transcripts go, which sub-processors touch them, and is audio used to train the vendor's models (can you opt out)?
7. Languages and accents
- Which languages does it genuinely handle well, and does the vendor report containment and error rates per language and accent group rather than a single blended number?
- An 80% aggregate can hide 45% for one caller segment.
8. Observability
- Can you see individual call transcripts, the reason for each escalation, and containment trends over time — or only a summary dashboard?
- Can you export the transcripts and the call data if you leave?
9. Evaluation and pricing
- Can you run it against your own historical call transcripts and see containment and error rates?
- Per-minute pricing, and how the bill behaves at your peak call volume.
How to weight it
Mostly-informational call volume makes sections 1, 2, and 5 the decision. Calls that qualify applicants or touch a decision make sections 3, 4, and 5 the whole thing — a vendor that can't act under your rules or hand off cleanly isn't a fit regardless of how smooth the demo was. Our voice AI engagement was scoped around exactly that: native speech-to-speech, actions through the client's own APIs, and a warm handoff triggered before any adverse-action line.
Red flags
- The demo is over wifi, not a phone line.
- "It handles compliance" with no specifics on consent records or the decision boundary.
- They won't run your historical transcripts.
- Cold transfer on escalation.
- Pricing that won't be quoted at your peak volume.
Where this checklist misleads
- Feature-counting. Weight by your actual call mix, not the longest capability list.
- A curated demo. Insist on your own transcripts and a live pilot on one intent.
- The smallest call volumes. A menu-based IVR may still be the right call.
FAQ
Build or buy — which does this point to? Either. Score vendors with it, or use the same questions as build requirements.
What's the single most important item? Native low-latency speech and a real warm handoff. Those two decide whether callers tolerate the line at all.
How long should evaluation take? Long enough to run your own historical transcripts and a live pilot on one intent group — weeks, not a demo call.
ISTRALLEN builds voice agents to this bar for financial-services call centres; see AI for Fintech.