eSIM Go are a dream partner for us. They made it incredibly easy to get up and running, and when our customers needed every new colleague on one monthly invoice, we asked and they built it.
Jenna Banks, Co-founder, SecondSim
SecondSim launched in January 2026, running on eSIM Go's platform for UK mobile plans, and now serves more than 4,000 UK businesses.
The challenge
Millions of UK sole traders, freelancers and small business owners run their business from their personal mobile number. It ends up on websites, invoices and marketplace listings, so clients call and text at all hours. Millions of people in the UK carry two phones to get around this, which is costly, clunky and one more device to charge.
The usual alternatives fall short. VoIP and virtual-number apps are cheap, but banks, WhatsApp and payment platforms often reject them at verification. For employers, the choice is just as poor: let staff use personal numbers with clients, or buy handsets on long, expensive business contracts.
SecondSim’s founders had previously led product and marketing at a start-up UK network. They had seen first-hand how easy it is to spend a lot of money building out a mobile experience, and they knew where the trapdoors were. The traditional MVNO playbook means heavy volume commitments, large up-front costs and long build times. They knew exactly what they wanted from a connectivity partner instead: simplicity, flexibility in capability and flexibility in budget.
The solution
SecondSim chose eSIM Go’s platform for UK mobile plans because it offered all three, letting the team rent the network rather than build one. Every SecondSim number runs on Vodafone UK, so customers get a real, carrier-grade mobile number that passes bank and WhatsApp checks first time.
With no large minimums, SecondSim could start small and grow at its own pace. eSIM Go’s APIs made development rapid, so the team could test a new proposition quickly and went live with its MVP in one week.
SecondSim consumes eSIM Go’s APIs and builds them directly into its own checkout, dashboard and team tools. That frees the team to focus on customer experience rather than the vagaries of telco. Five things make the difference:
Clear tools and documentation. eSIM Go’s APIs and documentation are easy to use, so a small team could integrate them quickly without telecoms specialists.
Connected in 60 seconds. Fast, programmatic provisioning means a customer pays, receives an eSIM link by email and has a working business line about a minute later. There is no plastic SIM, no contract and nothing to post.
Webhooks that keep customers informed. Robust webhooks and notifications let SecondSim update customers automatically at every step. The experience stays seamless, and fewer customers need to get in touch.
Fixed bundles. Plans are fixed bundles with nothing metered, so neither SecondSim nor its customers have to manage usage.
A partner that builds with you. eSIM Go supports SecondSim on new propositions, technical innovation and product development. When business customers began adding colleagues at different points in the month, SecondSim needed part-month billing so every line could land on one invoice. They asked eSIM Go, and eSIM Go put it straight onto the product roadmap.
A business tool, not a data bundle
Most new mobile brands compete on gigabytes, and a race to the bottom on data prices destroys margins. SecondSim avoided that race by changing what it sells.
A SecondSim plan is a business identity: a real UK number that works with WhatsApp Business, bank two-factor authentication and platforms like Stripe, PayPal and Amazon. SecondSim designed the bundle around how customers actually use a second line: unlimited UK calls and texts, with no data. The customer’s main SIM already covers their data, so they never pay for it twice, and the price stays low. Customers pay for an outcome they value, a clean line between work and home, from £5.99 a month.
That positioning came from listening. Before building, the founders interviewed tradespeople, freelancers and small business owners, and they have kept shaping the product around what those customers ask for next. Selling an essential tool rather than a commodity keeps ARPU healthy and customers loyal, and it gives SecondSim a story that travel and data-only eSIM brands cannot tell.
How it works
Sole traders and freelancers. SecondSim started with a single plan for one person: a real UK number with unlimited UK calls and texts, from £5.99 a month on a monthly, quarterly or yearly plan. There is no ID check and no contract, and the phone’s own dialler offers a personal or business line on every call. Customers can also port an existing number in.
Running a salon meant clients contacting me 24/7. There’s no more evening anxiety when my phone buzzes.
Caroline, The Basement Hairdressers, Manchester
Small teams. As early customers began asking for lines for their staff, SecondSim built a team dashboard. Owners issue, reassign and revoke business numbers on the phones employees already carry, with one VAT invoice a month, even when staff join mid-month, and volume discounts at 5 and 10+ lines. When someone leaves, the number and its client relationships stay with the business. It replaces second handsets and 24 to 36-month business contracts with a set-up that takes minutes.
Customers who need data. Pro Data adds unlimited UK data on Vodafone for £19.99 a month, for tethering, tablets and network failover.
AI assistants. SecondSim publishes its plans through Model Context Protocol (MCP) endpoints. When someone asks an AI assistant for a second business number on their phone, the assistant can check live plans and send them straight to checkout. AI assistants and agents are now SecondSim’s second-biggest acquisition channel, with no spend on search ads.
Support. Custom AI agents resolve 75% of support tickets around the clock and can take any back-end action a person could. When a person is needed, the team works through tickets asynchronously.
From one product to a platform
SecondSim is the first product built on its founders’ jolli platform, and the model is designed to repeat. A clear niche, an infrastructure partner that handles the network, and automation in place of headcount: the same approach could support further mobile brands on eSIM Go’s platform.
Published 7 October 2026