Twilio products · 2026
Twilio SIP trunk vs Programmable Voice: which one does a sales dialer use?
Last updated September 3, 2026
Twilio sells calls twice. Elastic SIP Trunking is a carrier service you point existing phone equipment at. Programmable Voice is an API that originates and controls calls itself. They have separate pricing pages, separate rate cards and separate consoles, and people shopping for a cold-calling setup routinely price the wrong one — usually the trunk, because it looks cheaper per minute. Here is what each is actually for, the real rate card for both, and the two-line rule for picking.
The short answer
If you run dialer software on your own server, you want an Elastic SIP Trunk — $0.0100 a minute outbound to the US 48, no channel fees. If you dial from a browser tab, you want Programmable Voice and you will never configure SIP: $0.0140 for the leg to the prospect plus $0.0040 for the WebRTC leg to your headset, $0.0180 all in. The trunk is about 44% cheaper per minute, which at 6,000 minutes a month is $48.00 — less than the cost of the server and the person who keeps it running.
What each product is for
| Elastic SIP Trunking | Programmable Voice | |
|---|---|---|
| Bought by | Someone who already has a phone system and needs a carrier for it | Someone building or using an application that makes calls |
| Connects to | Asterisk, FreePBX, Vicidial, 3CX, a softswitch, a UCaaS platform | A browser tab, a mobile app, or your own backend over the REST API |
| Call control | None. Twilio carries the call and stays out of it. | Full: TwiML, webhooks on every event, record, transcribe, conference, bridge, stream |
| You configure | A SIP domain, origination URIs, an IP access control list or credential list | An Account SID and Auth Token, a TwiML app, and a number |
| Runs where | Your server, which you patch and monitor | Twilio, plus the browser tab |
| Typical buyer | Contact centres, MSPs, anyone migrating off a legacy PRI | SaaS products, sales dialers, IVRs, notification systems |
The distinction that resolves most confusion: a trunk carries calls, it does not make them. If you want software to dial down a list, wait for an answer, drop a voicemail and write a disposition, something has to issue those instructions. On a trunk, that something is a dialer you host. On Programmable Voice, it is the application — which is why every browser-based dialer, including this one, is built on Programmable Voice.
The rate card, US, September 2026
| Line item | Rate | Which product |
|---|---|---|
| Outbound to US 48 states | $0.0100 | SIP trunk (termination) |
| Outbound to Alaska | $0.0862 | SIP trunk (termination) |
| Outbound to high-cost rural routes | $0.0620 | SIP trunk (termination) |
| Inbound to a local number | $0.0034 | SIP trunk (origination) |
| Inbound to a toll-free number | $0.0130 | SIP trunk (origination) |
| Outbound to a US number | $0.0140 | Programmable Voice |
| Inbound to a local number | $0.0085 | Programmable Voice |
| Browser or app leg (WebRTC) | $0.0040 | Programmable Voice |
| SIP endpoint leg (SIP Interface) | $0.0040 | Programmable Voice |
| BYOC trunk leg, each direction | $0.0040 | Programmable Voice + your carrier |
| Call recording | $0.0025 | Both |
| Recording storage, per minute per month | $0.0005 | Both |
| US local number, per month | $1.15 | Both |
| Emergency calling registration, per number per month | $0.75 | SIP trunk |
Twilio list prices from its US SIP trunking and voice pricing pages, checked September 2026; volume and committed-use discounts exist above these. Two things worth noticing. First, Elastic SIP Trunking has no per-channel charge and no concurrency limit, which is the headline difference against traditional trunk providers who sell you channels — you are not sizing a trunk, you are paying for minutes. Second, termination is zoned: the $0.0100 figure is the 48 contiguous states, and a list with Alaskan or rural high-cost numbers in it bills six to nine times that on those calls. Blended "starting at" rates hide this.
What a month costs at 1,000, 3,000 and 6,000 minutes
Outbound US 48 only, one local number, billed the way Twilio bills — per call, rounded up to the whole minute. Roughly, 1,000 minutes is a part-time caller, 3,000 is one full-time SDR, and 6,000 is about three.
| Route | Per min | 1,000 min | 3,000 min | 6,000 min |
|---|---|---|---|---|
| Elastic SIP Trunking + your own PBXTermination to the US 48 states. You supply and host the dialer software. | $0.0100 | $11.15 | $31.15 | $61.15 |
| Programmable Voice, browser dialer$0.0140 PSTN leg + $0.0040 browser leg. No server, no SIP. | $0.0180 | $19.15 | $55.15 | $109.15 |
| Programmable Voice, bridged to a mobileTwilio dials the prospect and dials the rep. Two PSTN legs, so double the rate. | $0.0280 | $29.15 | $85.15 | $169.15 |
The third row is there because it is the mistake that actually costs money. If a dialer "calls your mobile and then connects you to the prospect", Twilio is paying for two PSTN legs and you are billed $0.0280 a minute — $169.15 at 6,000 minutes, more than double the trunk. A browser leg costs $0.0040 instead of $0.0140. Dialing from the browser is not a convenience feature, it is a 35% discount on every minute; the mechanics are in how to make cold calls from your computer.
The cost the rate card does not show
The trunk wins on minutes and loses on everything else, because a trunk on its own does nothing. To dial a list with it you need dialer software, a server to run it on, and a person who can configure a SIP domain, an IP access control list, a dialplan and NAT traversal, and who will be the one reading a packet capture when one carrier's calls start failing at 3pm.
Put the saving next to that. At 6,000 minutes a month the trunk saves $48.00 against a browser dialer. A small VPS that can run an Asterisk-based dialer for a few agents is a similar order of magnitude on its own, before anyone's time. The break-even is not at three reps; it is somewhere north of 20,000 minutes a month, and even then it is a staffing decision rather than a telephony one. We costed the self-hosted route in detail in the Vicidial alternative guide — the short version is that free and open source is not free to run.
The genuine reasons to take the trunk anyway: you already have the PBX and the person, you need call concurrency in the hundreds, you want predictive dialing with agent queueing that only contact-centre software does, or you are connecting a system that has no API and only speaks SIP. Those are real. "It is a third of a cent cheaper" is not.
The three things at Twilio that are called SIP
Most of the confusion in this comparison comes from Twilio having three SIP-shaped products with different prices and purposes:
- Elastic SIP Trunking. Twilio as your carrier. Your PBX sends a call, Twilio delivers it to the phone network. $0.0100 out, $0.0034 in. No TwiML is involved at any point.
- SIP Interface, also called SIP Domains. Part of Programmable Voice. A SIP phone or softphone registers with Twilio, and calls to and from it run through your TwiML like any other leg — $0.0040 a minute for the SIP leg on top of the PSTN leg. This is what you use when you want application logic and a desk phone.
- BYOC trunking. The reverse of Elastic SIP Trunking: your existing carrier is connected into Programmable Voice at about $0.0040 a minute per direction, so Twilio controls the call while someone else carries the minutes and owns the numbers. For enterprises with carrier contracts or in-country regulatory requirements, not for a five-person sales team.
If a comparison article quotes you a single "Twilio SIP price" without saying which of these three it means, it has not checked.
Choosing, in two questions
Do you run, or want to run, calling software on a server you administer? If yes, buy an Elastic SIP Trunk, point your PBX at it, and price your dial plan by zone rather than by the headline rate. If no, go to the second question.
Do you want to dial from a browser? Then it is Programmable Voice, and there is nothing to decide — the dialer software makes that choice for you, and the only Twilio configuration you touch is an Account SID, an Auth Token and a number. On DialSheet that is Settings, then Twilio, then paste two credentials; about ten minutes including the Twilio signup. Twilio trial accounts cannot cold call, so the upgrade with a card comes first. The three ways to get a power dialer onto a Twilio account — build it, use Flex, or connect one — are laid out in the Twilio power dialer guide.
One thing does not change with the answer: caller ID rules, STIR/SHAKEN attestation and number reputation behave identically on both products, because they are properties of the numbers on your account rather than of the transport. Owning the account is what gets you A attestation and control over remediation, whichever product carries the call.
No SIP domain, no server, no dialplan
DialSheet is a browser power dialer on Programmable Voice, running on your own Twilio account at wholesale. Free for one person up to 500 calls a month; $29 a month for a 3-seat team. You keep the numbers, the recordings and the Twilio account.
Start freeQuestions people actually ask
What is the difference between Twilio Elastic SIP Trunking and Programmable Voice?
Elastic SIP Trunking is a carrier replacement: it hands your existing phone system — an Asterisk, FreePBX, Vicidial or 3CX box you run — a route to the public phone network over SIP, and Twilio does nothing to the call beyond carrying it. Programmable Voice is an API: Twilio originates and controls each call, you tell it what to do with TwiML or the Voice SDK, and it can record, transcribe, conference, bridge and stream. Trunking is plumbing you point a PBX at; Programmable Voice is the calling engine inside an application.
How much does Twilio Elastic SIP Trunking cost?
On Twilio's US list price, checked September 2026: termination (outbound from your PBX to the phone network) is $0.0100 a minute to the 48 contiguous states, origination (inbound to a Twilio number, delivered to your PBX) is $0.0034 a minute on a local number, and a US local number is ~$1.15/month. There is no per-channel fee and no concurrency limit, and encryption is included. Termination is zoned: Alaska is $0.0862 and high-cost rural routes $0.0620, which is where cheap-looking blended rates go wrong.
Should I use a SIP trunk for my sales dialer?
Only if you already run, or intend to run, dialer software on your own server — Vicidial, GoAutoDial, Asterisk with a dialplan you maintain. In that case the trunk is the right and cheaper product. If your dialer runs in a browser tab, it uses Programmable Voice through the Voice SDK and you never configure SIP at all: you paste an Account SID and Auth Token into the software and the WebRTC leg to your headset is handled for you. Choosing a trunk for a browser dialer is not a cheaper option, it is a product you cannot use.
Is a SIP trunk cheaper than Programmable Voice?
Per minute, yes: $0.0100 against $0.0180 for a browser call, so about 44% less. In absolute terms the gap is small at sales-team volumes. At 6,000 minutes a month — roughly three full-time cold callers — the trunk bill is $61.15 and the browser bill $109.15, a difference of $48.00. That saving has to cover a server, the dialer software, upgrades, SIP debugging and someone who can read a packet capture. Below roughly 20,000 minutes a month it rarely does.
What is BYOC trunking, and is it the same thing?
No. BYOC (Bring Your Own Carrier) trunking connects a carrier you already have a contract with to Twilio Programmable Voice, so Twilio controls the call logic while someone else carries the minutes and owns the numbers. Twilio charges about $0.0040 a minute for the connection in each direction, on top of whatever your carrier bills. It is for enterprises with existing carrier commitments or regulatory constraints. Elastic SIP Trunking is the opposite direction: Twilio is the carrier, and your equipment is the thing being connected.
Does a SIP trunk change my caller ID or STIR/SHAKEN attestation?
The rules are the same on both products. You can present a number you own on the account, or a caller ID you have verified. Full A-level attestation requires an approved business profile, a SHAKEN/STIR trust product and calling from numbers on your own Twilio account; verified caller IDs cap out at B. What a trunk changes is who sets the From header — your PBX does, which makes misconfiguration your problem rather than the software's, and a mismatched From on a trunk is a common cause of calls arriving unattested.
How does Twilio bill voice minutes?
Per call, rounded up to the next whole minute, on both Elastic SIP Trunking and Programmable Voice. A 65-second call bills two minutes; a ten-second voicemail hang-up bills one. Unanswered ringing costs nothing. This matters more for cold calling than for any other use case, because a dialing session is mostly short calls: a rep whose average connected call is 40 seconds is billed a full minute for each of them, so the practical rate is well above the sticker rate per talk-minute.