Best SIP Trunking Providers in 2026: 9 Options Compared (Rates, Routes, Support)

Quick answer: the best SIP trunking providers in 2026

For US businesses the strongest SIP trunking providers in 2026 are Signalmash (direct Tier-1 carrier routes, elastic trunks, engineer-staffed support, $0.0068/min outbound), Telnyx (own network, $0.005/min outbound, strong developer tooling), Bandwidth (a Tier-1 carrier itself, best for very large volumes on contract), Twilio Elastic SIP Trunking (widest ecosystem, higher list rates at $0.0100/min), Plivo, SignalWire, Vonage and Flowroute. The right pick depends on whether you value the lowest list rate, direct carrier control, or someone who answers the phone when a trunk goes down.

This article is part of the Signalmash SIP trunking resource series: what SIP trunking is, the best providers in 2026, what it costs, wholesale SIP for resellers and Twilio Elastic SIP alternatives.

Every SIP trunking provider claims carrier-grade quality and 99.99% uptime, so the brochure does not help you choose. What separates them is who actually owns the routes, how they bill, how they handle STIR/SHAKEN and E911, and what happens when something breaks. Here is how the main US options compare, with the criteria we used to rank them.

How we compared providers

• Route ownership: does the provider interconnect directly with AT&T, Verizon, T-Mobile and Bandwidth, or resell a wholesale aggregator? Direct routes mean fewer hops, better audio and faster fault-finding.
• Pricing model and transparency: published per-minute rates, channel fees, number rental and hidden extras such as E911 and recording.
• Elasticity: can capacity grow automatically for a campaign or seasonal peak without buying channel packs?
• Compliance: STIR/SHAKEN full attestation, branded caller ID, E911 with dispatchable location, CNAM.
• Support: who you reach, how fast, and whether they can read a SIP trace.
• Fit: PBX and contact center integrations, BYOC support, portal and API quality.

1. Signalmash

Best for: growing businesses and contact centers that want direct carrier routes and real humans on support.

Signalmash is a US CPaaS and carrier with direct interconnects to AT&T, Verizon, T-Mobile and Bandwidth. Trunks are elastic with no channel packs; the Launch plan has no monthly minimum and no channel fee up to 10 calls per second. Published rates: $0.0068/min outbound to the lower 48, $0.0053/min inbound local, $0.0018/min outbound toll-free, numbers $0.95/month. STIR/SHAKEN attestation, branded caller ID and automatic failover are included, and support runs through a dedicated Slack channel with an engineer in it. Signalmash also handles SMS, MMS and RCS on the same account, which matters if your PBX or contact center needs texting from the same numbers. Details on the SIP trunking page and pricing page.

Weak spots: US and Canada focus only; if you need native termination in 60 countries, look at Telnyx or Twilio.

2. Telnyx

Best for: developer-led teams that want the lowest list rate on an owned network.

Telnyx runs its own private IP network and is a licensed carrier in the US, which lets it publish very low rates: about $0.005/min outbound and $0.0032/min inbound, numbers $1.00/month. Portal and API are excellent, international coverage is broad, and there are no platform fees. Support is ticket and chat based; enterprise support costs extra.

3. Bandwidth

Best for: very high-volume enterprises and platforms that want a Tier-1 carrier under contract.

Bandwidth owns a nationwide network and is one of the carriers everyone else interconnects with. Rates are negotiated rather than fully public (third-party comparisons put outbound around $0.0035 to $0.008/min), minimum commitments apply, and onboarding is enterprise-style. Excellent for platforms sending millions of minutes; heavy for a 50-seat PBX.

4. Twilio Elastic SIP Trunking

Best for: teams already built on Twilio's programmable voice and messaging.

Twilio coined the term "elastic SIP trunking" and its product is mature: unlimited concurrent calls, secure trunking, a global footprint and deep documentation. List rates are the highest on this list at $0.0100/min outbound to the US 48 and $0.0034/min inbound local, with numbers at $1.15/month and E911 at $0.75/number/month. Support beyond email requires a paid plan. See our Twilio Elastic SIP alternatives comparison.

5. Plivo

Best for: API-first companies wanting a Twilio-style toolkit at lower rates.

Plivo's Zentrunk SIP product lists around $0.0055/min outbound and inbound with numbers near $0.80/month, good global coverage and a straightforward console. Enterprise support is an add-on.

6. SignalWire

Best for: FreeSWITCH and Asterisk shops that want low rates and programmable media.

Built by the FreeSWITCH team, SignalWire lists roughly $0.0055/min outbound and $0.0050/min inbound with numbers at $0.85/month. Strong for developers building their own voice applications; less hand-holding for a standard PBX migration.

7. Vonage Business (Nexmo)

Best for: organisations that want SIP trunks and UCaaS from one vendor.

Vonage's SIP trunking lists near $0.0139/min outbound and $0.009/min inbound with numbers around $1.50/month. The value is the bundle with Vonage's contact center and unified communications products rather than the per-minute price.

8. Flowroute (BCM One)

Best for: small and mid-size PBX deployments that want simple pay-as-you-go trunks.

Flowroute has been a favourite of FreePBX and 3CX installers for years: competitive per-minute rates, easy number porting and a clean portal. It is now part of BCM One, and support is largely self-service.

9. voip.ms

Best for: very small businesses and hobbyists.

Extremely cheap (about $0.009/min outbound, $0.0085/min inbound, numbers from $0.85/month), highly configurable, community-supported. Not built for contact center volumes or enterprise SLAs.

Comparison table

Provider	Outbound US (per min)	Inbound local (per min)	Number (per month)	Direct Tier-1 routes	Support model
Signalmash	$0.0068	$0.0053	$0.95	Yes (AT&T, Verizon, T-Mobile, Bandwidth)	Slack channel with engineers
Telnyx	$0.005	$0.0032	$1.00	Own network	Ticket/chat; paid enterprise tiers
Bandwidth	~$0.0035–0.008 (contract)	~$0.0050	$0.50–1.50	Is a Tier-1 carrier	Enterprise account teams
Twilio	$0.0100	$0.0034	$1.15	Aggregated	Email; paid support plans
Plivo	~$0.0055	~$0.0055	$0.80	Aggregated	Ticket; paid enterprise
SignalWire	~$0.0055	~$0.0050	$0.85	Aggregated	Community + ticket
Vonage	~$0.0139	~$0.009	$1.50	Aggregated	Standard business support
voip.ms	$0.009	$0.0085	$0.85+	Aggregated	Ticket/community

Rates quoted are publicly listed US pay-as-you-go prices as of September 2026; every provider changes prices and offers committed-use discounts, so confirm on the provider's pricing page before you decide.

How to choose

• Under 1 million minutes a month and you want someone to call: Signalmash or Flowroute.
• Developer team, global coverage, lowest list price: Telnyx.
• Already on Twilio programmable voice: stay on Twilio Elastic SIP unless price forces a move.
• Tens of millions of minutes and a procurement team: Bandwidth on contract.
• Contact center bringing its own carrier to Five9, Genesys, NICE or Talkdesk: Signalmash or Bandwidth, both of which support BYOC; see the SIP trunking for contact centers guide.

Talk to a Signalmash voice engineer about your call volumes, PBX and number inventory, and we will quote a SIP trunk with the exact per-minute rates you will pay.

People also ask

Who is the best SIP trunking provider in the USA?

It depends on volume and support needs. Signalmash suits growing businesses and contact centers that want direct AT&T, Verizon, T-Mobile and Bandwidth routes with engineer-staffed support; Telnyx has the lowest published list rates on its own network; Bandwidth is the choice for very large contracted volumes; Twilio fits teams already on its platform.

What is the cheapest SIP trunk provider?

On published US list rates, Telnyx (about $0.005/min outbound) and Bandwidth (contract rates from about $0.0035/min) are cheapest, followed by Plivo, SignalWire and Signalmash in the $0.0055 to $0.0068 range. Twilio and Vonage list the highest rates at $0.010 to $0.014/min. Total cost also depends on channel fees, number rental and add-ons such as E911.

What should I look for in a SIP trunking provider?

Direct carrier interconnects rather than resold routes, published per-minute pricing with no channel packs, STIR/SHAKEN full attestation, E911 with dispatchable location, automatic failover, compatibility with your PBX or contact center platform, and support that can read a SIP trace within minutes rather than days.

Can I use SIP trunking with Microsoft Teams?

Yes. Microsoft Teams Direct Routing lets you connect a certified session border controller to a SIP trunking provider so Teams users can make and receive PSTN calls at per-minute rates instead of Microsoft Calling Plan prices. Most providers on this list, including Signalmash, support Direct Routing through an SBC.