Why now. And how big.
Simma is built to work in any country, so every business in the world is the ceiling. Service businesses are the market. Service businesses with up to nine staff are where Simma starts. Subscriptions plus payments, from official counts in the UK and the US — every number and every assumption shown.
- TAM~£392bn a year
Every business in the world, sole traders to enterprises, priced to local incomes. £114bn in the UK and US. estimate
- SAM£62bn a year
UK and US service businesses with fewer than 250 staff — 19.0m. measured counts
- BEACHHEAD£44bn a year
UK and US service businesses with up to nine staff — 17.9m. Where Simma starts. measured counts
- SOM£173m run rate by the end of year five
50,000 customers: 47,000 micro, 2,500 small, 498 medium and 2 enterprise — £116.5m of revenue in year five, 0.28% of SAM. target
A huge market, and Simma needs only a sliver of it. The SOM comes from the plan (the customer ramp below, by year, channel, country and business size), not from a percentage of the market.
AI can do the work now. It needs somewhere to do it.
AI can finally do the work. It needs a golden record to do it on.
Agents can now answer the enquiry, book the class, chase the invoice and write the post — work that used to need staff. But an agent can only finish a job where everything it touches lives in one place: the timetable, the payment, the customer. A small business keeps those in five tools.
The golden record is the missing piece — and whoever holds it is where the work gets done.
AI operating systems connect to the tools. None of them owns the record.
A new category of AI "operating systems" reaches into other companies' software over APIs. They can read and draft; the record — and the finish — stays with someone else.
Discovery is moving to AI answers.
People ask an assistant for "a pilates class near me on Thursday". It answers from structured, public records — a business needs to own them.
The next wave of businesses starts with nothing to switch from.
797,769 new UK companies in twelve months (Companies House, July 2025 to June 2026) and 531,728 US business applications in August 2026 alone (US Census Bureau). As AI reshapes corporate jobs, we expect more people to start businesses around what they love (vision), and a new business has no stack to migrate.
Who the businesses are, how many, and how much they turn over.
Official statistics for the UK, the US and the EU; the best available estimates for the world. Each size band uses the UK, EU and OECD standard.
Businesses × what each one pays Simma.
Counts from the UK's Business Population Estimates 2025 and the US Census Bureau (2022), for businesses of every size. Revenue per business = the plan tier for its size, plus the Simma Pay margin on its measured turnover.
The worldwide TAM, by income group
Method: UK + US spend per head (£278, all business sizes) scaled by each group's income per head relative to the UK and US (US$83,000 a head, World Bank) — the equivalent of pricing Simma to local incomes — times the group's population. World Bank 2025 population and GNI per head (Atlas method).
What each business pays Simma — the workings, size by size
Sole traders on Lite (£49) or Starter (£99); 1–9 staff on Business (£199, 10 users) — plus the Simma Pay margin on turnover.
- UK revenue per business£2,435
- US revenue per business£2,436
- UK: 5.34m × £2,435£13.0bn
- US: 23.56m × £2,436£57.4bn
- Subscription / payments47% / 53%
Pro, £299 a month for 25 users, + £5 a month for each extra user — plus the Simma Pay margin (0.75% + 5p).
- Average staff (UK and US)20
- Subscription £299 × 12£3,588
- UK revenue per business£11,987
- US revenue per business£13,316
- Subscription / payments28% / 72%
Scale, £499 a month for 50 users, + £5 a month for each extra user — plus the Simma Pay margin (0.75% + 5p).
- Average staff (UK)96
- Subscription (£499 + 46 × £5) × 12£8,748
- UK revenue per business£61,473
- US revenue per business£60,093
- Subscription / payments14% / 86%
A custom contract, modelled at £10 per employee per month. No payments revenue — enterprises invoice and use their own processors.
- Employees (UK / US)10.4m / 81.3m
- UK: 10.4m × £10 × 12£1.3bn
- US: 81.3m × £10 × 12£9.8bn
- At £25 a seat instead£95bn world
- Subscription / payments100% / 0%
Where the payments margin comes from
Rates from Simma's plan (April 2026). Lite is assumed to share Starter's rate, and Pro Scale's. These rates sit above the headline card rates of Square or SumUp — which is why the sensitivity below also prices Simma Pay at a flat 1%.
Method and sources
- Service businesses: UK sections F, I, M, N, P, Q, R, S; US NAICS 23, 54, 56, 61, 62, 71, 72, 81. Consumer services assume 60% of turnover through Simma Pay; trades, professional and other sectors assume 20%, because more of their income is invoiced.
- Plan tier by size: solo — Lite or Starter; 1–9 staff — Business; 10–49 — Pro; 50–249 — Scale. US solo filers under $10k of receipts are excluded. $1.30 = £1.
- SAM and beachhead stay UK + US: they are where today's product, pricing and Simma Pay work, and they grow country by country as payments launch.
- Counts, employment and turnover: UK Business Population Estimates 2025 (Table 5, every industry section and size band); US Census Bureau Nonemployer Statistics 2022 (solo filers over $10k) and Statistics of US Businesses 2022 (detailed employment sizes).
- Revenue per business uses each industry's own turnover and headcount, so averages differ by country. Simma Pay: 60% of turnover in consumer services, 20% elsewhere.
- The US 200–299 band straddles 250 staff and is split half to medium, half to enterprise. 89,000 UK businesses in suppressed cells are left out. $1.30 = £1.
- World: each band's UK + US spend per head, scaled to each World Bank income group by income per head (×3.43 overall). An estimate.
From the first studios to 50,000 customers.
Not a percentage of a big market — customers by year, by channel, by country. Paying customers at the end of each year.
- Gusto — small-business payroll: about 100 customers in its first year, 10,000 by its third.
- Toast — restaurant platform: 1,000 customers in its first five quarters; about 29,000 customers (48,000 locations) at its IPO, eight years in.
- HubSpot — small-business marketing: about 600 customers after its first year; 100,000 customers some thirteen years in.
Simma's ramp sits between them: faster than Toast in customer count — Simma's price per customer is far lower — and slower than Gusto's breakout.
A plan, not a forecast: the channel mix and yearly totals are targets. Year 1 includes the pre-seed milestone of ten paying studios by month six; years 2–5 assume the seed and Series A rounds that fund growth. Small and medium customers come mostly through franchise and multi-location groups from year three; the first two enterprise customers arrive in year five. Churn by size is an assumption for small-business software.