One Potato underneath everything.
Picture a baked potato. The network is the potato. Services - intelligence, Agents, recording, fraud blocking - are layers of foil wrapped around it. Transports like SIP, Teams, WhatsApp Calling and the PSTN are skewers pushed straight through the lot: any call in on any skewer, out on any other, any service applied on the way through. And our Global Edge stretches the skewers worldwide.
ONE POTATO, THE WHOLE BUSINESS · FOIL = SERVICES · SKEWERS = TRANSPORTS · EVERY TRANSPORT AT EVERY EDGE · The full story →
Carrier Services.
Numbers, termination, trunks, SMS and interconnect: the substrate hundreds of operators rely on, API-first since 1996.
Hosted.
The platform you put your own brand on: PBX, SIP trunks and residential, with everything included in the seat price.
Conversational AI.
Agents that answer your phones: unscripted, goal-driven, live in under a minute. A capability of Carrier Services and Hosted alike - your brief, your knowledge, your rules.
Conversation Intelligence.
Operators that watch for what matters on the calls you choose, acting mid-call with webhooks and whispers. Yours to switch on, and off - per trunk, per number, per call.
Real AI needs a real network underneath
Anyone can rent GPUs. Nobody can rent a carrier. Whether you want a thousand clean numbers or an AI Operator on every call, it's the same wholly owned Potato underneath - 30 years of PSTN scar tissue included.
100% SLA · last outage 2018
Global Edge on four continents · three UK availability zones
Direct interconnects with all four UK mobile networks
Profitable, debt-free, employee-owned
CLEC in 21 US states · wholly owned network
AI Voice platforms. CCaaS. CPaaS. SaaS with voice inside.
If your product lives or dies on the network underneath it, stop paying a middleman for ours. Who builds on us, and why
Even our sternest critics rate the network 8 out of 10.
We surveyed customers at the end of 2025 and, being us, we're showing you the honest numbers. On the thing a carrier exists to do - keeping calls up and sounding good - everyone agreed: call quality averaged 9.4 and not one respondent, promoter or detractor, scored reliability below 8. The network is the product. That's the number that matters.
"I never have to worry that Simwood is going to be down."
SURVEY RESPONDENT · on the value they get"If Simwood disappeared tomorrow? Frankly, I'd probably just stop bothering to be a VoIP provider full stop."
SURVEY RESPONDENT · on what they'd miss"Leaps ahead of competitors with API, webhooks, interop."
SURVEY RESPONDENT · on what drives their score"In an industry full of helmets, you are not helmets."
SURVEY RESPONDENT · on why they'll stayBest is a boast. Only is a fact.
Every carrier claims to be the best something. We'll skip that. These are onlys: check them, and tell us if we're wrong.
We've been early before. Every time, actually.
A 2026 platform is only credible from a company with form. Ours goes back three decades, and the pattern is consistent: build the thing years before the industry admits it matters. Some in our market preach stability while standing still; standing still is the easy kind. Stability while shipping something new most weeks is the kind worth paying for. And where there's a choice between integrity and money, integrity wins: we block the fraud and nuisance traffic other carriers happily bill.
First API ships
They weren't called APIs then; they were called web services. Some of our competitors still don't have usable ones.
Encryption for everyone
TLS and SRTP across the network while the industry insisted nobody wanted it. Still free on every call.
Fraud, fought not billed
Three years of honeypot research published free, real-time fraud controls in the API, back when the industry's answer was to bill the victim.
Containerised core
A container-based carrier network a decade before the industry, while much of it was still catching up on virtualisation.
The network, rebuilt
Routers out, L3 switches and SDN in; the only comparable operation at scale was Spotify. Anycast inside the network gave us load balancing, service discovery and fault tolerance by design.
America, properly
Simwood Inc: our own PoPs and CLEC licences, a real carrier in the US rather than a reseller. Now licensed in 21 states.
The 100% SLA
25x credits if we're ever down, launched months after our last outage to date. No maintenance windows, because a network with no single point of failure doesn't need them.
Sipcentric joins
The acquisition that brought us hosted voice and Charles, the CTO who insisted on doing everything properly. The 2026 platform is the proof he was right.
Spoofed CLI, blocked
Invalid caller ID rejected network-wide years before regulation required it, and among the first 1% signing STIR/SHAKEN in the US.
BYoC
Bring your own carrier - to a carrier. Nuts on paper, exactly the point in practice: our platform on anyone's numbers, no porting required.
The nuisance-call stand
Blocking nuisance and scam calls outright, inbound and outbound - now roughly 5% of all attempts on the network. No other carrier will.
Conversational AI live
AI voice agents on any number, on any carrier that routes to SIP. Unscripted, goal-driven, defined by you.
Conversation Intelligence
Real-time AI in the call path itself. The biggest thing we've ever shipped, in beta now.
One thread runs through all of it.
Caller ID integrity in 2013. Fraud research given away in 2014. Invalid CLI blocked in 2020. Nuisance calls refused outright in 2025, roughly 5% of everything we could have billed. Nobody made us do any of it, and all of it cost us money. That's the point. Doing the right thing when it isn't profitable is why you can trust us in your call path. It's a specific metric on every staff appraisal here.
"I'd rather be alone and right than in good company and wrong."
SIMON WOODHEAD · FOUNDER & CEOLatest from the blog.
Internal documentation that actually gets used: ADRs, MCP servers, and AI-accessible knowledge
Part 12 of 12 – Conversation Intelligence Platform series Back to Part 1 There’s a category of engineering problem that doesn’t show up in postmortem…
Documentation as a first-class product: narrative guides, live OpenAPI, and Scalar
Part 11 of 12 – Conversation Intelligence Platform series Back to Part 1 Most API documentation in telecoms is a reference dump. A list of endpoints.…
Deprecation as a feature: how we migrate a 200-endpoint API without breaking customers
Part 10 of 12 – Conversation Intelligence Platform series Back to Part 1 “We’re retiring this endpoint” is a statement that has earned its bad reputa…
The carrier AI platform nobody had built yet? We just built it.
Conversation Intelligence is live on the network now, and the interactive documentation is the fastest way to see it working: real endpoints, real signals, no sales call required. Agents, Operators, Actions and Memory, on your numbers or anyone else's. And when you want a human, we have those too.