Quick answer: On each vendor’s published US list rates, read 28 September 2026, an AI voice agent running 100,000 minutes a month (60% outbound, WebSocket media streaming, 20 local numbers) costs US$1,643 on Twilio Programmable Voice and US$998 on the Telnyx Voice API. Telnyx’s SIP rates are “from” figures; Twilio’s Programmable Voice outbound rate is flat across the US except Alaska.
That gap holds on the SIP-trunk path too (US$759 against US$448), and it is structural rather than a rounding artefact: both carriers bill in whole minutes, so the same calls produce the same billed minutes on either bill. What differs is how each vendor slices the invoice. Twilio Programmable Voice bundles the carrier leg into one per-minute rate per direction. Telnyx publishes two lines, a US$0.002 Voice API fee plus the Elastic SIP trunk the call rides. Around both sit the add-ons an AI agent actually uses: Twilio Media Streams or Telnyx media streaming over WebSockets, answering machine detection, call recording, call transfer, and a hosted speech layer (Twilio ConversationRelay, Telnyx Voice AI Agents). Frameworks such as Pipecat and LiveKit Agents connect to either carrier, so the choice is mostly about the bill, the audio codecs you can stream, and the outbound dialling rules.
Is Twilio or Telnyx cheaper for my AI voice agent?
On published US list rates, Telnyx’s total is lower on both paths of the worked scenario below, and lower on every line except the $0.002 Voice API fee that Twilio bundles into its call rate, and the gap in that outbound-heavy scenario is roughly 40% of the carrier bill. It is not lower on every add-on: Twilio lists lower rates for conferencing and emergency calling, and both list $0.10 for a transfer (on Twilio that is the per-refer charge for a SIP REFER from its SIP interface). That is what the numbers show for the stated scenario; it is not a verdict on either company, and it moves once volume discounts, committed-use contracts or a non-US destination mix enter the picture. Twilio says volume and committed-use discounts are available on its US Voice pricing page; Telnyx lists a Committed plan “from $500 / mo” and an Enterprise plan “from $5,000 / mo” on its SIP Trunking pricing page. Neither vendor publishes the per-minute calling rates those volume or committed tiers unlock, so this page prices list rates only.
The caveat that matters most is the word “from”. Telnyx publishes US outbound SIP as “Starting at $0.005 per minute” and inbound local as “Starting at $0.0032 per minute”, and points to a downloadable rate deck for per-destination rates. Twilio publishes US and Canada outbound at a flat $0.0140 per minute (Alaska is $0.0945). So the Twilio side of the programmable calculation below is the rate you will pay to a lower-48 number; the Telnyx side is the floor. Twilio’s Elastic SIP Trunking is priced per destination too: the same page that lists “United States – 48 States (Zone 1)” at $0.0100 a minute lists “United States – High Cost (Zone 4)” at $0.0620, so on the trunking path neither side’s rate is certain until you check the numbers you dial. The sensitivity table further down shows how far the Telnyx outbound rate would have to rise before the totals cross.
One sentence to carry away: on US list rates the carrier leg for an AI voice agent costs about one US cent a minute on Telnyx and about 1.6 US cents on Twilio once media streaming is included, and the rate for your actual destinations is the number to confirm before you sign.
What each vendor actually charges per minute in the US
These are the lines an AI voice agent touches, read from each vendor’s own pricing page on 28 September 2026. Twilio’s pages state “Pricing current as of August 2026”. All figures are US dollars, pay-as-you-go, before any volume tier.
| Line item (US) | Twilio | Telnyx |
|---|---|---|
| Platform or API fee per minute | Bundled into the call rate (Programmable Voice) | $0.002/min Voice API fee, charged on top of the SIP trunk |
| Outbound call to a US local number, programmable path | $0.0140/min (US and Canada; Alaska $0.0945) | $0.002 Voice API + SIP outbound from $0.005 = from $0.007/min |
| Inbound call to a local number, programmable path | $0.0085/min | $0.002 Voice API + SIP inbound from $0.0032 = from $0.0052/min |
| Outbound, SIP trunking only (your own media server) | $0.0100/min, “United States – 48 States (Zone 1)” termination; “United States – High Cost (Zone 4)” is $0.0620/min | From $0.005/min |
| Inbound, SIP trunking only, local number | $0.0034/min origination | From $0.0032/min |
| WebSocket media streaming | Media Streams $0.0044/min | Media Streaming over WebSockets $0.0035/min |
| US local number rental | $1.15/month | From $1.00/month; $0.79 each for the next 200 once you buy more than 50 in a month |
| Billing increment | Partial minutes rounded up to the next full minute, per leg | 60/60: an 11-second call bills as 60 seconds |
Two things in that table catch people out. First, Twilio’s SIP trunking page headlines termination “Starting at $0.0011 / min”, but the detailed network pricing on the same page shows that $0.0011 is the “United States – Toll Free” route; a call to a lower-48 number is $0.0100. Second, the Telnyx programmable path is always two lines: Telnyx’s own Voice API page says outbound calls are “$0.002 per minute + the SIP Trunking fee”, so comparing Twilio’s $0.0140 with Telnyx’s $0.002 on its own understates the Telnyx bill by the trunk.
A worked monthly bill: 100,000 minutes, 60% outbound
This is the citable part of the page, and every input is a published rate you can substitute. The scenario uses the same 60/40 split that Telnyx’s own Voice API pricing page uses for its US$628 example, extended to include the two lines an AI agent cannot avoid: a media stream to your speech pipeline, and phone numbers.
Assumptions, stated so you can change them: 100,000 billed minutes a month; 60,000 outbound to US lower-48 local numbers; 40,000 inbound to US local numbers; every minute streamed to your own speech-to-text, model and text-to-speech pipeline over a bidirectional WebSocket; 20 US local numbers rented. Model, speech and hosting costs are excluded on purpose; they are the same whichever carrier you pick, and they are priced on our separate page on what AI voice costs per minute for realtime and pipeline architectures.
| Line | Twilio Programmable Voice + Media Streams | Telnyx Voice API + media streaming |
|---|---|---|
| Voice API fee | n/a (bundled) | 100,000 × $0.002 = $200.00 |
| Outbound, 60,000 min | 60,000 × $0.0140 = $840.00 | 60,000 × $0.005 = $300.00 |
| Inbound, 40,000 min | 40,000 × $0.0085 = $340.00 | 40,000 × $0.0032 = $128.00 |
| WebSocket media streaming, 100,000 min | 100,000 × $0.0044 = $440.00 | 100,000 × $0.0035 = $350.00 |
| 20 local numbers | 20 × $1.15 = $23.00 | 20 × $1.00 = $20.00 |
| Monthly total | $1,643.00 | $998.00 |
| Per billed minute | $0.01643 | $0.00998 |
The difference is $645.00 a month, and the biggest single contributor is the outbound line: $840 against $500 once the Telnyx Voice API fee on those 60,000 minutes ($120) is added to the trunk ($300). Media streaming is the second-largest line on both bills, and Telnyx’s own $628 example on its Voice API page includes neither media streaming nor number rental.
If you run your own SIP media server (LiveKit’s SIP service, Asterisk, FreeSWITCH or similar) and use the carrier as a trunk only, there is no Voice API fee and no per-minute streaming charge, because the audio arrives as RTP at your server:
| Line | Twilio Elastic SIP Trunking | Telnyx Elastic SIP |
|---|---|---|
| Outbound (termination), 60,000 min | 60,000 × $0.0100 = $600.00 | 60,000 × $0.005 = $300.00 |
| Inbound (origination), 40,000 min | 40,000 × $0.0034 = $136.00 | 40,000 × $0.0032 = $128.00 |
| 20 local numbers | 20 × $1.15 = $23.00 | 20 × $1.00 = $20.00 |
| Monthly total | $759.00 | $448.00 |
| Per billed minute | $0.00759 | $0.00448 |
Here the difference is $311.00 a month, and almost all of it is outbound: inbound origination is within $0.0002 a minute on the two published rate cards. Whether trunking is worth the engineering at all is a separate question, worked through on our page asking whether an AI voice agent needs its own SIP trunk.
How far can the Telnyx “from” rate rise before the answer changes?
Because Telnyx’s outbound figure is a floor, the honest way to present the comparison is as a threshold. Holding every other line in the scenario fixed, this is the Telnyx outbound SIP rate at which each Telnyx total would equal the Twilio total:
| Path | Twilio total | Telnyx lines other than outbound SIP | Break-even Telnyx outbound rate | Multiple of the published floor ($0.005) |
|---|---|---|---|---|
| Programmable voice + WebSocket streaming | $1,643.00 | $200 + $128 + $350 + $20 = $698.00 | ($1,643 − $698) ÷ 60,000 = $0.01575/min | 3.15× |
| SIP trunking only | $759.00 | $128 + $20 = $148.00 | ($759 − $148) ÷ 60,000 = $0.01018/min | 2.04× |
Read it as a decision rule: if the Telnyx rate deck prices your actual outbound destinations below about $0.010 a minute, Telnyx’s list rates are lower on both paths for this call mix; between about $0.010 and $0.016, only the programmable path stays lower; above $0.016, the published Twilio rates are lower on both. Pull the destinations you really dial, look them up in the Telnyx deck, and the table tells you which side of the line you are on. The same logic applies to Twilio outside the lower 48: a list heavy with Alaska numbers is priced at $0.0945 a minute on Twilio’s programmable page and would move the totals far more than any other input here, and on the trunking path Twilio prices “United States – High Cost (Zone 4)” destinations at $0.0620 a minute, so check your list against Twilio’s termination rates as well as the Telnyx deck.
The charges that are not on the per-minute line
Most surprises on a carrier bill for an AI agent come from per-call and per-feature lines, not from the minute rate. These are the ones each vendor publishes for the US, read 28 September 2026:
| Add-on | Twilio | Telnyx |
|---|---|---|
| Answering machine detection | $0.0075 per call | Standard $0.002 per call; premium $0.0065 per call |
| Call recording | $0.0025/min, plus storage $0.0005/min per month | $0.002/min; storage $0 per minute |
| Call transfer | Refer from Twilio (SIP interface) $0.1000 per refer | $0.10 per invocation |
| Conference | Starting at $0.0018 per participant per minute | $0.002 per participant, per minute |
| Emergency calling | $0.75 per month per number | $1.5 per month, per number (SIP Trunking page) |
| Hosted speech layer, you bring the model | ConversationRelay $0.07/min | Conversation Relay $0.05/min |
| Hosted voice-agent engine with orchestration | See the capability table below | Voice AI Agents $0.05/min (orchestration, speech-to-text, text-to-speech; model tokens and telephony extra) |
| Outbound calls-per-second | 1 CPS at no charge on pay-as-you-go; “Provision up to 30 CPS in the console” | SIP Trunking only: first 5 CPS free, then graduated from $12 per CPS on the monthly 95th-percentile peak |
The calls-per-second row, and one Telnyx surcharge that sits outside the table, deserve a sentence each, because outbound AI dialling is exactly the traffic they describe. Telnyx’s help article on its calls-per-second surcharge says the surcharge is calculated on “outbound SIP Trunking call attempts” and lists “Programmable Voice / Call Control traffic” as excluded, so it applies to the trunking path, not to the Voice API path. The graduated rates are “First 5 CPS = free”, then $12 per CPS up to 25, $16 up to 200, $24 up to 250 and $30 above that, measured at the 95th percentile of each active hour’s peak. Telnyx’s article on abandoned call surcharges counts a call as abandoned when the originating side hangs up “during the ringing/call set-up process”, and states that “Calls to disconnected numbers also count”. If more than 20% of outbound calls meet that definition, the $0.005 applies to all of the abandoned calls, not just the excess. A dialler with a short ring timeout and an uncleaned list can cross 20% without anyone noticing, so it is worth measuring before launch. On the Twilio side, the calls-per-second figures above are the only ones visible as text on the page; prices for higher CPS sit in an interactive calculator we could not read, so we have not printed them.
Rounding is a wash between the two in the US: Twilio rounds partial minutes up to the next full minute per leg, and Telnyx describes its US billing as 60/60. Short calls are expensive on both for the same reason, which is covered in detail on our page explaining why an AI voice agent bill is higher than minutes times the rate.
What is different for an AI voice agent, apart from price?
Every cell below comes from the vendor’s own documentation or pricing page, read on 28 September 2026. Where a vendor’s page makes a claim about itself (such as coverage counts), the cell says so.
| Capability | Twilio (own docs) | Telnyx (own docs) |
|---|---|---|
| Bidirectional WebSocket audio to your agent | Yes. Bidirectional Media Streams via <Connect><Stream>; the stream receives the inbound track only; “you can have only one Stream per Call” | Yes. Set stream_bidirectional_mode to rtp; “The number of bidirectional RTP streams per call is limited to 1” |
| Audio format on the stream | audio/x-mulaw at 8000 Hz; the docs say the value is “always” that | PCMU 8 kHz (default), PCMA 8 kHz, G722 8 kHz, OPUS 8 or 16 kHz, AMR-WB 8 or 16 kHz, L16 16 kHz |
| Elastic SIP trunking | Yes; “Unlimited Call Concurrency” and SRTP/TLS secure trunking included | Yes; call concurrency and secure trunking listed as free; optional inbound channels from $12 per month |
| Regions and edges | Eight public edge locations (Sydney, Sao Paulo, Dublin, Frankfurt, Tokyo, Singapore, Ashburn, Umatilla); Media Streams available in the IE1 and AU1 regions, default US1 | Telnyx states “130+ countries of local calling”, “230+” countries for international SIP trunking and carrier licences in “30+ countries” |
| Phone numbers | “over 100 locales”; US local $1.15/month | US local from $1.00/month, volume tiers down to $0.25 at 5,000+ numbers |
| Hosted AI layer | ConversationRelay (Twilio handles speech recognition and text-to-speech; your app supplies the model’s text); Virtual agent with Google Dialogflow CX, listed on the US Voice pricing page; Twilio Agent Connect, an SDK described as “middleware between your LLM applications and Twilio services” | Voice AI Agents, a no-code assistant built in the Telnyx portal with a model, voice and number; also Conversation Relay and TeXML, which Telnyx says runs a TwiML application “unchanged” |
| LiveKit SIP trunk setup guide | Yes, “Create and configure a Twilio SIP trunk” | Yes, “Create and configure Telnyx SIP trunk” |
| Pipecat serialiser | TwilioFrameSerializer, documented by Pipecat | TelnyxFrameSerializer, documented by Pipecat with PCMU and PCMA encodings |
The codec row is the most consequential difference for teams building their own pipeline. Twilio Media Streams hands your server 8 kHz mu-law, so a speech model that wants 16 kHz linear PCM needs a resample step. Telnyx documents an L16 16 kHz option and says it “provides improved support for AI voice agent integrations by offering reduced latency and eliminating transcoding overhead”. Whether you get that benefit depends on your framework: Pipecat’s own documentation for its Telnyx serialiser lists PCMU and PCMA, so a Pipecat pipeline on Telnyx streams the same 8 kHz telephony audio it would on Twilio unless you change the serialiser. For how the Twilio options compare with each other, see our page on Twilio ConversationRelay versus Media Streams for AI agents.
The hosted-AI row is not like for like. Twilio ConversationRelay at $0.07 a minute and Telnyx Conversation Relay at $0.05 a minute are both speech layers in front of a model you run. Telnyx’s Voice AI Agents engine at $0.05 a minute also includes orchestration, and Telnyx prices model tokens and telephony separately on the same page. If you are comparing hosted layers, compare the scope first and the price second.
Who each option is the wrong choice for
Twilio is the wrong choice if the only thing that matters to you is the lowest published US per-minute rate on a large outbound programme. On the scenario above the published list difference is $645 a month, and it scales linearly with minutes; a committed-use discount may close it, but you only find that out by asking.
Telnyx is the wrong choice if your stack already leans on Twilio products that a carrier switch does not carry over, if your destinations price above roughly $0.010 a minute in the Telnyx deck and you are on the trunking path, or if you are on the programmable path and need exactly one flat, published US outbound rate for budgeting rather than a per-destination deck. Telnyx says TeXML runs TwiML “unchanged”; test the specific verbs your application uses before you rely on that.
Neither decision is permanent. Pipecat documents serialisers for both carriers and LiveKit publishes a SIP trunk setup guide for each, so the framework layer does not lock you in. Nothing stops you running one carrier for inbound and another for outbound; the cost of running two is a second account, a second set of number registrations and a second dashboard, not a rebuild.
How to check this against your own call mix
- Export last month’s call records. Split minutes by direction (inbound or outbound) and by destination type (local, toll-free, Alaska and Hawaii, international). A billed-minutes column is better than a duration column, because it already carries the 60-second rounding.
- Count the add-on events: calls with answering machine detection, transfers, recorded minutes, and the percentage of outbound calls that ended before answer. That last figure decides whether the Telnyx abandoned-call surcharge applies.
- Price each vendor’s lines from its own page. Telnyx’s pricing pages carry comparison tables that quote Twilio figures; use Twilio’s own page for Twilio’s rates and Telnyx’s own page for Telnyx’s.
- Look up your top outbound destinations in the Telnyx rate deck and compare them with the break-even rates in the threshold table above.
- Test the audio path you will actually run: codec, sample rate and your framework’s serialiser, on a real call, before you move numbers.
If you would rather not own this layer at all, the choice moves inside whichever vendor runs your agents, and the useful questions become which carrier they use and whether per-minute telephony is passed through or bundled. Zian’s phone, SMS, email and WhatsApp sales agents are in a partnership-application beta; the carrier comparison above is the one to run if you are building the agent yourself.
Frequently asked questions
Is Telnyx cheaper than Twilio for AI voice calls in the US?
On published US list rates read on 28 September 2026, yes for the scenario on this page: 100,000 minutes a month at 60% outbound with WebSocket streaming comes to $998 on Telnyx and $1,643 on Twilio. The Telnyx outbound figure is a starting rate, so check your own destinations in the Telnyx rate deck before relying on it.
Does Telnyx charge the $0.002 Voice API fee on top of SIP trunking?
Yes. The Telnyx Voice API pricing page describes outbound and inbound calls as $0.002 per minute plus the SIP Trunking fee, so a US outbound programmable call is at least $0.007 a minute. Customers using the SIP trunk alone, without the Voice API, pay only the trunk rate.
How do Twilio and Telnyx round call minutes?
Both round up to the whole minute for US calls. Twilio states in its help article on how voice minutes are rounded for billing that partial minutes under 60 seconds are rounded up to the next full minute, including for Media Streams and Elastic SIP Trunking. Telnyx describes 60/60 billing increments in its help article on billing increments, where an 11-second call is charged as 60 seconds.
Which one supports 16 kHz audio for my AI voice agent?
Telnyx documents bidirectional streaming codecs including L16 at 16 kHz, OPUS at 8 or 16 kHz and AMR-WB at 8 or 16 kHz. Twilio documents Media Streams audio as mu-law at 8000 Hz. Check your framework too: Pipecat documents PCMU and PCMA for its Telnyx serialiser.
What does media streaming cost on Twilio and Telnyx?
Twilio lists Media Streams at $0.0044 a minute on its US Voice pricing page. Telnyx lists Media Streaming over WebSockets at $0.0035 a minute on its Voice API pricing page. On 100,000 streamed minutes that is $440 against $350.
Does Telnyx charge for outbound calls abandoned before answer?
Telnyx publishes a surcharge of $0.005 per abandoned call when more than 20% of outbound calls are abandoned by the caller during ringing or set-up, and calls to disconnected numbers count as abandoned. At or below 20%, this surcharge does not apply.
Where every figure on this page comes from
| Figure | Who published it | Link | Date read |
|---|---|---|---|
| US outbound $0.0140/min, inbound local $0.0085/min, Alaska $0.0945/min, Media Streams $0.0044/min, ConversationRelay $0.07/min, local number $1.15/month, AMD $0.0075/call, recording $0.0025/min and storage $0.0005/min per month, Refer from Twilio $0.1000, conference from $0.0018, Virtual agent with Google Dialogflow CX listed, emergency calling $0.75/month, 1 CPS free and up to 30 CPS in the console, “over 100 locales”, “Pricing current as of August 2026” | Twilio | twilio.com/en-us/voice/pricing/us | 28 September 2026 |
| Elastic SIP termination $0.0100/min (48 States, Zone 1), High Cost (Zone 4) termination $0.0620/min, toll-free termination $0.0011/min, local origination $0.0034/min, unlimited call concurrency and SRTP/TLS secure trunking included | Twilio | twilio.com/en-us/sip-trunking/pricing/us | 28 September 2026 |
| Partial minutes rounded up to the next full minute, per leg | Twilio | help.twilio.com article 223132307 | 28 September 2026 |
| Bidirectional Media Streams, inbound track only, one bidirectional Stream per Call, IE1 and AU1 regions | Twilio | twilio.com/docs/voice/media-streams | 28 September 2026 |
| Stream audio “always” audio/x-mulaw at 8000 Hz | Twilio | twilio.com/docs/voice/media-streams/websocket-messages | 28 September 2026 |
| Eight public edge locations | Twilio | twilio.com/docs/global-infrastructure/edge-locations | 28 September 2026 |
| ConversationRelay handles speech recognition and text-to-speech | Twilio | twilio.com/docs/voice/conversationrelay | 28 September 2026 |
| Twilio Agent Connect described as SDK middleware | Twilio | twilio.com/docs/conversations/agent-connect | 28 September 2026 |
| Voice API $0.002/min plus SIP trunking, $628 example (100,000 minutes, 60% outbound), media streaming $0.0035/min, Conversation Relay $0.05/min, AMD $0.002 and $0.0065 per call, recording $0.002/min, storage $0, transfer $0.10, conference $0.002 | Telnyx | telnyx.com/pricing/voice-api | 28 September 2026 |
| US outbound from $0.005/min, inbound local from $0.0032/min, inbound channels $12/month first 10, call concurrency and secure trunking free, emergency calling $1.5/month, Committed from $500/month, Enterprise from $5,000/month | Telnyx | telnyx.com/pricing/elastic-sip | 28 September 2026 |
| US local numbers from $1.00/month, $0.79 next 200 above 50 a month, $0.25 at 5,000+ | Telnyx | telnyx.com/pricing/numbers | 28 September 2026 |
| Voice AI Agents voice engine $0.05/min, model tokens billed separately | Telnyx | telnyx.com/pricing/voice-ai-agents | 28 September 2026 |
| TeXML runs a TwiML application “unchanged” at $0.002/min | Telnyx | telnyx.com/pricing/texml | 28 September 2026 |
| 60/60 billing increments | Telnyx | support.telnyx.com article 1130659 | 28 September 2026 |
| CPS surcharge tiers (5 free, $12, $16, $24, $30), SIP Trunking only, Call Control excluded | Telnyx | support.telnyx.com article 7834487 | 28 September 2026 |
| Abandoned call surcharge $0.005 above 20% | Telnyx | support.telnyx.com article 12805746 | 28 September 2026 |
| Bidirectional codecs PCMU, PCMA, G722, OPUS, AMR-WB, L16; one bidirectional stream per call | Telnyx | developers.telnyx.com media streaming | 28 September 2026 |
| No-code voice assistant in the Telnyx portal | Telnyx | developers.telnyx.com voice assistant quickstart | 28 September 2026 |
| 130+ countries of local calling, 230+ countries for SIP trunking, licences in 30+ countries | Telnyx | telnyx.com/global-communications | 28 September 2026 |
| Telnyx serialiser supports PCMU and PCMA | Pipecat | docs.pipecat.ai Telnyx serialiser | 28 September 2026 |
| Twilio serialiser for Media Streams | Pipecat | docs.pipecat.ai Twilio serialiser | 28 September 2026 |
| Telnyx SIP trunk setup guide | LiveKit | docs.livekit.io Telnyx provider | 28 September 2026 |
| Twilio SIP trunk setup guide | LiveKit | docs.livekit.io Twilio provider | 28 September 2026 |
| Worked totals ($1,643, $998, $759, $448) and break-even rates ($0.01575, $0.01018) | Zian, calculated from the rows above | This page | 28 September 2026 |