Twilio alternatives for voice agents

The main Twilio alternatives for a voice agent are Telnyx, Vonage, Plivo, SignalWire, Sinch and Bandwidth, and the right one depends on which countries your callers are in. Most publish some rates, for example on Twilio's and Telnyx's own pages, and a few publish none. This guide lists what we could read in the UK, the US and Australia, says where we could not, and does not rank anyone.

Key facts

• Twilio lists a UK local number at $3.50 a month and a US one at $1.15 (UK page, US page).
• Plivo lists a UK local number at $0.85 a month and a US one at $0.50 (UK page, US page).
• SignalWire's public rates cover the US and Canada, and other countries go through a request form (rates, international services).
• Bandwidth prices by volume and lists no per-number prices (Bandwidth).
• Twilio gives each account one call per second by default for calls placed through its API (Twilio docs).

What do the carriers charge for UK numbers and calls?

Prices are in US dollars, pay as you go, as each carrier prints them. Plivo's and Twilio's UK rates were read on 31 October 2026. The rest come from our phone carriers page, read on 29 October 2026. We list carriers alphabetically.

Read the notes behind these numbers before you compare them. Vonage also prints a cheaper domestic card, but the page says that access needs a sales contact. Simwood says its full rate sheets are for active customers. Sinch prints one outbound figure and does not split landline from mobile. Twilio adds separate rows for calls from surcharged zones, and the page gives $0.2293 a minute for one of them.

What do they charge outside the UK?

The UK is our proof point, but a voice agent can sit anywhere. We read the US and Australian pages on 31 October 2026 where the carrier publishes them. Our phone carriers page only holds UK rates, so every figure below is new to this guide.

Where a cell says "Not read", we tried and could not get a figure. Vonage refused our automated request for its pricing page on 31 October. Sinch's page showed placeholder zeros until a country was chosen, and we did not rely on them. Telnyx loads one country at a time and showed us only the US. Telnyx also lists a US local number at $1.00 a month on its number pricing page, which is the figure in the table.

SignalWire says that by default its spaces are enabled only for the US and Canada, and that you ask for other countries through a request form. Sinch says its elastic SIP trunking is available in the US and Canada. Plivo's rates page notes that they were last updated in May 2026, and Twilio's says August 2026, so check the date on the page you use.

How do you compare these fairly?

Not like for like. A "starting at" or "from" rate is the cheapest route, not a promise for every call. Rates differ between landline and mobile, between a number you receive on and one you call, and sometimes by where the call starts. The same per-minute figure can also mean different things, since some carriers round up to a billing step. Bandwidth, for example, says it bills in 6-second increments.

So work out your own mix before you read any table. Count how many minutes are inbound and outbound, and for outbound how many go to mobiles. Add the number rental for each line you need. Then check that rate on the page for each country you serve. A voice agent that rings out to mobiles will see a different bill from one that only answers a landline queue.

Our platform pricing guide shows the same exercise for the voice agent platform's own fee, which sits on top of whatever the carrier charges.

Will your voice agent platform work with them?

Most platforms take a SIP trunk, so the carrier does not have to be on a short list. The lists below are what each platform's docs name, and not a test.

• ElevenLabs says it is compatible with most standard SIP trunk providers, including Twilio, Vonage, Sinch, Telnyx, Plivo and Bandwidth.
• Retell has setup guides for Twilio, Telnyx and Vonage, and says other providers that support SIP trunks work too.
• LiveKit says it supports third-party SIP trunking providers, and names Telnyx, Twilio, Plivo and Wavix.
• Pipecat's repository lists serializers for Twilio, Telnyx, Plivo and Vonage.

SignalWire and Simwood are not named in any of those lists. That does not mean they fail, since these docs say other SIP providers work. It does mean you should test the first call before you commit.

What else should you check before you move?

Number rules. Each country has its own rules for who may hold a number, and the carriers describe them on separate pages. For UK numbers, Twilio asks for a UK address and identity documents, and Telnyx asks for an ID copy and a utility bill less than three months old. Plivo's docs say that the UK, the US, Canada and Australia do not require compliance documents, which is one reason to read each carrier's page for your own country rather than assume.

Where the call is processed. Twilio says its default Region is US1, in the eastern United States, and it also offers an Ireland region in Dublin. Vonage's EU endpoint processes calls in Dublin, with Frankfurt as the fallback. Telnyx's EU point of presence runs in Frankfurt, and it says storage location is a separate setting. If your callers are in the UK or EU, this affects both delay and privacy.

Caller ID on outbound calls. In the UK, Ofcom's guidance says calls with inaccurate caller ID should be stopped or blocked. Expect a carrier to reject a number you cannot show you hold.

Call limits. Twilio's default of one call per second through its API matters if your agent places a lot of outbound calls at once. We have not read the limits for the other carriers.

How do you test a carrier before you switch?

Put the same agent on the new line and ring it from a mobile, a landline and a call from abroad if you take those. Listen for gaps, clipped starts and echo. RingTru's simulated callers are built to ring a number and talk to the agent. Our guide to test calls for a phone agent covers what to check on each call, and the IVR and call testing guide covers keypad tones, silence and transfers. Phone-line audio also changes what speech recognition hears, as we explain in UK accents on phone audio.

Where we have not tested yet

We have not placed a test call over any of these carriers. Every price in this guide is a printed list price, not a bill we paid, and we have not measured delay or call quality on any of them. Rates for Vonage and Sinch outside the UK, and for Bandwidth and Telnyx in Australia, are missing because we could not read them. Our phone carriers page covers UK carriers only and says RingTru has run no tests of its own on them.

These guides name vendors in plain text and are not endorsed by any of them.