What is a Fractional CFO?

Advice

What is a Fractional CFO?

A fractional CFO is an experienced chief financial officer who works with your business on a part-time or retainer basis — typically 1 to 4 days per month. They bring the same expertise as a full-time CFO but without the full-time salary.

For SaaS, AI and tech founders in the UK, a fractional CFO gives you senior-level financial leadership at the exact stage you need it — before you can justify a £150,000+ full-time hire.

What Does a Fractional CFO Actually Do?

A fractional CFO covers every area of your company's finances at a strategic level. In practice, that means:

Financial modelling — building 3-year forecasts, scenario planning, MRR/ARR projections
Cash flow forecasting — knowing your runway, when you might run out of cash, and what levers to pull
Monthly reporting — board packs, investor updates, management accounts
Fundraising support — financial models investors trust, due diligence prep, data room organisation
Exit planning — cleaning up financials, maximising valuation, preparing for acquisition
Budgeting — working with team leaders on 12-month budgets tied to hiring and growth plans
Financial data accuracy — fixing messy chart of accounts, correct revenue recognition, COGS vs OPEX

Fractional CFO vs Full-Time CFO

A full-time CFO in the UK typically costs £120,000–£200,000 per year in salary alone, plus benefits and equity. A fractional CFO costs £2,000–£5,000 per month depending on scope — roughly £24,000–£60,000 per year.

For most SaaS founders below £5M ARR, a fractional CFO delivers more value because you get a senior operator who has seen dozens of companies at your stage, not a generalist building experience on your dime.

Who Needs a Fractional CFO?

You are likely ready for a fractional CFO if:

Your ARR is above £300K–£500K and growing fast
You are preparing to raise a seed or Series A round
Your financial data feels messy or hard to explain to investors
You are spending too much time on finance instead of product and sales
You have a board or investors expecting proper reporting
You are planning an exit in the next 2–3 years

How Much Does a Fractional CFO Cost in the UK?

Most fractional CFOs in the UK charge a fixed monthly retainer. Typical ranges:

Early stage (seed): £1,500–£3,000/month
Growth stage (Series A prep): £3,000–£5,000/month
Pre-exit or fundraising: £4,000–£7,000/month

At ScaleWithCFO, we work on a fixed monthly retainer so founders always know what they are paying — no billable hours, no surprise invoices.

Fractional CFO vs Accountant vs Bookkeeper

This is one of the most common questions founders ask. Here is the difference:

Bookkeeper — records transactions, reconciles bank, runs payroll. Backward-looking.
Accountant — prepares year-end accounts, files tax returns, ensures compliance. Backward-looking.
Fractional CFO — uses financial data to drive decisions, plan growth, support fundraising, and manage risk. Forward-looking.

Most SaaS founders have a bookkeeper and an accountant. What they are missing is the forward-looking financial leadership that a fractional CFO provides.

Frequently Asked Questions

How many hours does a fractional CFO work per month?

Typically 8–20 hours per month, depending on the scope. During a fundraising round or exit process, this can temporarily increase.

Do I need a fractional CFO if I already have a finance manager?

Yes — a finance manager handles day-to-day operations. A fractional CFO provides strategic leadership, investor-facing output, and the experience to handle complex financial decisions your finance manager may not have faced before.

Can a fractional CFO help with fundraising?

Absolutely. Building the financial model, preparing for investor questions, organising the data room, and supporting due diligence are core fractional CFO responsibilities.

Written by Constantin Botnari, Chartered Accountant & Fractional CFO for SaaS, AI and tech founders in London & UK. Connect on LinkedIn.