Almost half the turnover sits with 8,335 firms; 4.3 million businesses are one person.
An audience brief, category level: financial products and services sold to businesses, from banking and lending to the software the finance function runs on. Built from the public shelf and the size-band method. Everything below is public and cited, and nothing comes from inside any account.
The biggest B2B finance segment is one person.
Claire, 38
Runs her own business, no staff
Does the banking on Sunday night, in the app she already had.
- 4,272,535 businesses like hers employ nobody but the owner note 1
- ≈50% of smaller businesses use no external finance note 4
- 963,700 titled finance people in the UK; she is not one of them note 2
Illustrative composite. Not a real person.
The universe is a barbell
Of the UK’s 5.7 million businesses, 4.3 million employ nobody but their owners. At the other end, 8,335 businesses employ 250 or more people and hold 49% of private sector turnover. The middle is thinner than the word “SME” implies: 220,085 small firms and just 38,435 medium ones.
Three quarters of the market has no finance department, no procurement and no committee, because it is one person, who does the banking on Sunday night.
The revenue-weighted end is a few thousand accounts that buy through committees over quarters.
The people with the job titles
The three finance occupations sum to 963,700 people. Every “target CFOs” plan is chasing a slice of under a million, most of them not in market.
The targetable finance population has a published size. Financial managers and directors: 461,400 people. Chartered and certified accountants: 233,600. Finance and investment analysts and advisers: 268,700. Together, 963,700.
The titled finance audience is 963,700 people, not a market of millions.
Every “target FDs and CFOs” media plan is chasing some slice of under a million people, most of whom are not in market for anything this quarter. The same million is also the audience for brand work: the large majority of them are not buying anything this quarter, which is the case the channel piece makes in general form.
The moment that matters
317,000 businesses formed in 2024, each buying a full financial stack in weeks. Challenger banks took gross SME lending flow from 39% in 2012 to 60% now; that the switch happens at formation is my read, not something the series shows.
317,000 new businesses formed in 2024. A new business acquires its entire financial stack in its first weeks: account, software, insurance, often an accountant. New firms are also where the incumbents lose. Challenger and specialist banks now take 60% of gross SME lending, up from 39% in 2012. The switching happened at the front door, not through mid-life churn. Around half of smaller businesses use external finance at all, so the other half is a consideration audience nobody has converted yet.
Challengers took 39% to 60% of gross SME lending flow.
The segments
Five buyers: the owner-operator, the first-finance-hire firm, the mid-market FD, the enterprise committee, and the week-one firm cutting across all four.
The owner-operator, 4.3 million strong: buys like a consumer, on memory and convenience. The finance function and the household budget are the same brain. The first-finance-hire firm: the one-to-49 band where an office manager or a first accountant takes over buying, the point where the product has to survive a second opinion. The mid-market FD: a named, findable person from the 963,700, running a proper evaluation on a cycle. The enterprise committee: thousands of accounts, procurement-led, where media supports a sales team rather than replacing one. And cutting across all four, the week-one firm: any of the above, in week one, with everything to buy and no incumbent.
What I would do
Market to owner-operators as consumers, buy share of voice with the sub-million titled audience, and fund the week-one moment permanently.
The owner-operator plan is consumer marketing wearing a B2B category, with products explained in one sentence. The titled-buyer plan is a sub-million-person audience where share of voice is affordable and the work is being remembered until the buying window opens. Fund the week-one moment separately and permanently, because 317,000 firms a year enter that state and the challenger-bank share says they convert. Size every piece of it from the public tables and cite them, so the numbers hold up when someone checks.
Where this argument is weakest
The occupation counts are rounded survey estimates, the lending shares come from a government-owned bank’s report, and the unregistered 3.0 million are invisible to the register.
The occupation counts are survey estimates, rounded, and job titles are a loose proxy for buying authority. The BBB lending figures come from a government-owned development bank’s market report, marked as such rather than official statistics. The BBB counts almost 314,000 new businesses in 2025 by its own method. The ONS counts 317,000 in 2024 by another. Putting both in one sentence would be number laundering, so I have not. And the register cannot see the unregistered 3.0 million, who are real businesses with real banking needs, reachable only as consumers. And the named person in the card is a composite, assembled from the figures in the notes.