What's the difference between fractional and outsourced CFO?

Nothing meaningful. Both terms describe a senior finance leader who works part-time for your business on a retainer instead of joining the payroll. Different firms use different labels for the same service.

At what revenue should a business hire a full-time CFO?

Usually somewhere between £15m and £25m turnover, depending on complexity. Below that a fractional CFO plus an internal finance manager or controller almost always delivers more per pound. Above £25m you typically need someone in-seat.

How much does a full-time CFO cost in the UK?

£110,000 to £180,000 a year fully loaded. That covers salary of £90,000 to £150,000, bonus, employer NIC at 13.8%, pension, and benefits. Recruitment fees add another 25 to 30% of base salary in year one.

Can a fractional CFO manage a finance team?

For a team of 1 or 2, yes. Once you have 3 or more people in finance they need daily line management, and a fractional CFO can't provide that from 2 days a month. The usual fix is to hire a finance manager or controller internally and keep the fractional CFO above them.

When should we switch from fractional to full-time?

When the fractional CFO is regularly billing 3.5 or more days a month, when finance headcount hits 3 or more, when you're preparing for a Series B or complex acquisition, or when investors have made it a condition of funding. Any two of those together usually means it's time.

Fractional CFO vs full-time CFO: which does your business need?

"Fractional CFO" and "outsourced CFO" mean the same thing: a senior finance leader who works with your business part-time on a monthly retainer instead of joining the payroll. The real question isn't the label, it's when you should switch from that model to a full-time hire.

Here's how the two compare in a UK SME context.

The short answer

£1m to £5m turnover: fractional CFO, almost always.
£5m to £15m: fractional CFO with an in-house finance manager or controller doing the day-to-day.
£15m+: start thinking about full-time. Above £25m turnover, you usually need one in-seat.

The tipping point is less about revenue and more about how much of a CFO's week the business actually needs. If they'd be busy 4-5 days a week, hire full-time. If they'd be busy 1-2, fractional wins on cost and access to seniority.

Cost comparison

Full-time CFO (UK)

Base salary: £90k-£150k
Bonus / LTIP: £10k-£40k
Employer NIC (13.8%): £12k-£22k
Pension, benefits, insurance: £8k-£15k
Total loaded cost: £110k-£180k per year

Plus recruitment fees (25-30% of base) and 6-12 months to get someone in seat.

Fractional CFO

1 day a month: £1,500-£2,500 per month (£18k-£30k a year)
2 days a month: £2,500-£5,000 per month (£30k-£60k a year)
3-4 days a month: £5,000-£9,000 per month (£60k-£108k a year)

No employer NIC, no pension, no recruitment fees. In seat within 2-4 weeks.

At every point below full-time, fractional is cheaper and faster to start. It only stops being cheaper when the business needs someone genuinely full-time.

What each model gives you

Fractional CFO strengths

Seniority for a fraction of the cost. You get someone who has run finance in bigger businesses, without paying big-business salaries.
Speed to start. Weeks, not months.
Flexibility. Scale up during a funding round, scale back after.
No hiring risk. If it doesn't work, you switch. No redundancy costs, no PILON, no drama.
Wider pattern library. A fractional CFO usually works with 4-8 clients, so they've seen more scenarios than someone spending 5 years at one company.

Full-time CFO strengths

Deep, in-the-business context. Present at every leadership meeting, every customer conversation, every hire.
Team leadership. If you have a finance team of 3+ people, they need daily line management.
Investor and board face-time. For scale-ups raising serious money, investors expect a full-time CFO by Series B.
Complex operational finance. Multi-entity, multi-currency, complex revenue recognition, or M&A integration is easier with someone in-seat.

Where fractional falls short

Two situations where fractional stops being enough:

Finance team management. Once you have 3+ people in finance, they need a manager who's around every day. A fractional CFO can't line-manage a team from 2 days a month. Solution: hire a finance manager or controller internally, keep the fractional CFO above them.
Board and investor intensity. Some VCs and PE firms will push for a full-time CFO before Series B. If your investors are going to make it a condition, plan for the transition rather than fight it.

The hybrid model most SMEs actually use

The pattern that works for 80% of businesses between £1m and £15m:

Fractional CFO: 2-4 days a month for strategy, forecasting, board reporting, funding.
Finance manager or controller: full-time internal, £45k-£65k, running month-end, AP/AR, payroll.
Bookkeeper: 1-2 days a week or outsourced, doing data entry and reconciliation.

Total cost: £70k-£110k. Delivers most of what a £150k CFO would, plus everything below them.

When to switch to full-time

Rough signals that it's time:

The fractional CFO is billing 3.5+ days a month and still can't cover the workload.
Finance team is 3+ people and needs daily leadership.
You're preparing for Series B, an exit, or a complex acquisition inside 12 months.
The board or investors have flagged it directly.
Turnover is £20m+ and growing 30%+ a year.

Any two of those together usually means it's time.

How we work

Calibra CFO runs on a monthly retainer, typically 2-4 days a month, with the option to flex up around funding rounds or big commercial decisions. See Calibra CFO or book a scoping call.