Twilio vs Telnyx for Voice AI in 2026: SIP, Per-Minute Cost, and Reliability

Published: April 28, 2026 Updated: April 28, 2026 Reading time: 9 minutes

Telephony is the part of the voice AI stack that everyone underestimates until production. Twilio is the default. Telnyx is the cheaper challenger. The right answer depends on call volume, geography, and how willing you are to operate carrier-side.

This is a side-by-side from the perspective of a voice AI builder — not a generic CPaaS comparison. We care about media-stream latency, programmable SIP, per-minute economics at scale, and how each carrier behaves when your AI agent has to dial out at 9am EST when 40 other companies are also dialing out.

TL;DR

• Twilio — the safer default. Best documentation, most mature SDKs, broadest global PSTN footprint, premium per-minute price.
• Telnyx — meaningfully cheaper per minute (often 30–50% lower), tighter SIP control, slightly thinner SDKs. Best when US/CA volume dominates and per-minute cost compounds.
• For voice AI specifically, both are first-class. Burki ships native adapters for both and either works for production.

Per-minute economics (US, April 2026)

Public pricing on the standard rate cards. Volume discounts not included.

For a voice agent doing 100,000 outbound minutes/month at the US local rate:

• Twilio: ~$1,300/month
• Telnyx: ~$700/month
• Annual gap: ~$7,200

That gap is meaningful for high-volume outbound. For a 5,000-minute/month inbound IVR replacement, the gap is ~$25/month — not enough to switch carriers over.

Global coverage

This is where Twilio still wins for international work.

• Twilio — DIDs in 100+ countries, mature local-number provisioning in Europe, APAC, LATAM, and the Middle East. KYC and number-port workflows are well-documented.
• Telnyx — DIDs in ~40 countries with strongest coverage in US, CA, UK, AU, DE, FR, NL. International expansion ongoing but trails Twilio.

If you need a Brazilian DID, a UAE DID, or a Singapore toll-free, Twilio gets you there faster. If 95% of your traffic is US/CA, Telnyx covers you.

Programmable SIP

Both carriers expose programmable SIP trunking and both work cleanly with Burki's media-stream adapter. Differences:

• Twilio Voice WebSocket — battle-tested, well-documented, predictable latency. Burki's media-stream pipeline was originally built against Twilio's protocol.
• Telnyx WebSocket Stream — newer, slightly more flexible (you can hook into the stream at multiple points), but you'll find fewer Stack Overflow answers when something breaks.

In production voice AI, both yield comparable end-to-end latency once you're past initial setup. We've measured ~50–80ms difference favoring Telnyx on some routes, but the noise on individual calls swamps the carrier difference.

SIP trunking and BYO

Both carriers support BYO carrier — i.e., you bring your existing termination provider, they handle the AI media-stream side. This is the right pattern when you have an existing telephony contract you can't break, or when you want to use a regional carrier for local-rate compliance.

Burki supports the BYO pattern on top of either Twilio or Telnyx — see Burki + Twilio and Burki + Telnyx.

Reliability

Public status pages tell most of the story:

• Twilio — has had two major (>30 min) global incidents in the last 18 months, both resolved within 2 hours. Regional incidents (single-DC) more frequent but typically don't impact a multi-region voice AI.
• Telnyx — has had one major (>30 min) global incident in the same window, resolved within 90 minutes. Generally tighter operational record but a smaller footprint to compare against.

For high-availability voice AI, the right answer is multi-carrier failover. Burki supports automatic carrier failover at the assistant level — define a primary and a fallback, and a Twilio outage routes to Telnyx (or vice versa) without dropping the agent.

SMS hand-off

A common pattern in production voice AI is: agent asks "should I text you the link?" → SMS goes out → call ends. Both carriers support SMS, but:

• Twilio — SMS deliverability is the gold standard, especially for short codes and 10DLC compliance.
• Telnyx — solid for 10DLC and toll-free SMS, less so for international SMS routes.

If SMS is a meaningful part of your conversation flow, Twilio is the safer pick.

Compliance

• Twilio — HIPAA-eligible (BAA available on Enterprise), SOC 2, GDPR, ISO 27001. The full alphabet soup.
• Telnyx — HIPAA-eligible, SOC 2, GDPR. Slightly thinner certification list but covers the common requirements.

For healthcare voice AI, both are workable. Make sure to sign the BAA before going live.

When to pick Twilio

• US/global mix where you need a Brazilian or APAC DID next month
• High SMS volume where deliverability matters
• Team familiar with the Twilio ecosystem from prior projects
• Outbound volume <50,000 minutes/month (the per-minute gap doesn't compound enough to justify migration)
• Compliance-heavy industry where the broader certification list matters

When to pick Telnyx

• US/CA-dominant traffic with >50,000 outbound minutes/month
• Cost-sensitive deployments where carrier line-item is a meaningful % of unit economics
• Want tighter SIP-level control (e.g., custom SIP headers, advanced routing logic)
• BYO carrier scenarios where Telnyx is your termination layer

When to pick both

• High-availability voice AI for any volume
• Geographic split (e.g., Twilio for international DIDs, Telnyx for US/CA volume)
• Negotiation leverage — having a working second-carrier integration gives you real leverage with your primary

How Burki abstracts the carrier choice

Burki's telephony adapter layer means switching carriers is a config change, not a code change. The same assistant prompt, the same STT/LLM/TTS pipeline, the same business logic — only the carrier-specific webhook and media-stream URL change.

You can run a 50/50 A/B between carriers in production for two weeks, measure call-completion rate, perceived audio quality, and per-minute cost, then commit. We've seen customers find a clear winner within 5,000 calls.

Recommendation

For most voice AI builders launching in 2026, the path of least regret is:

1. Start on Twilio because the docs and ecosystem support are unmatched.
2. Once you're past 50,000 outbound minutes/month, integrate Telnyx as a secondary carrier.
3. Run a 50/50 split on outbound for 2 weeks, measure, commit to the winner for that traffic class.
4. Keep the loser as your failover carrier.

Both Burki + Twilio and Burki + Telnyx integrations are first-class and pass through wholesale rates in BYO mode.

Try Burki on either

Start Free — 200 minutes, BYO Twilio or Telnyx keys supported from day one.