Fractional CFO for SaaS & AI Startups in London

Why London SaaS and AI Founders Need a Specialist CFO

London is one of the most active SaaS and AI startup ecosystems in Europe. With access to world-class investors, a deep talent pool, and a growing enterprise customer base, London-based tech founders are scaling faster than ever.

But rapid growth creates financial complexity that generalist accountants are not equipped to handle. MRR schedules, unit economics, investor-grade financial models, data rooms — these require a CFO who has done it before, in SaaS and AI specifically.

What a London-Based Fractional CFO Does for SaaS Founders

Financial modelling — Investor-ready 3-year models with MRR, churn, CAC/LTV, burn rate, and scenario analysis
Monthly reporting — Board packs and investor updates that reflect true business performance
Cash flow forecasting — Always knowing your runway and the cash impact of every major decision
Fundraising support — From Innovate UK loans and EIS/SEIS to Series A and beyond
Exit preparation — Cleaning up financials, building the data room, maximising valuation
Financial data cleanup — Fixing messy chart of accounts, revenue recognition, COGS vs OPEX

London SaaS & AI: Specific Financial Considerations

Innovate UK funding — Grant and loan reporting requirements, milestone tracking, compliance
EIS/SEIS schemes — Many London angel investors expect SEIS/EIS advance assurance; a fractional CFO keeps you compliant
Multi-currency revenue — London SaaS companies often sell in GBP, EUR and USD simultaneously
R&D tax credits — A significant cash benefit for qualifying tech companies that many founders underutilise

What to Look for in a Fractional CFO for SaaS & AI

Direct SaaS or tech company experience — not just general SME finance
Familiarity with SaaS metrics: MRR, ARR, churn, CAC, LTV, net revenue retention
Experience supporting fundraising rounds and investor due diligence
Fixed retainer model — not day rates with unpredictable billing
Strong references from founders, not corporate finance clients

ScaleWithCFO: London-Based Fractional CFO for SaaS & AI

Constantin Botnari is a Chartered Accountant and fractional CFO based in London, specialising exclusively in SaaS, AI and tech founders. Clients range from seed-stage startups to companies preparing for strategic exits.

ScaleWithCFO works on a fixed monthly retainer — no day rates, no billable hours, no surprises.

Frequently Asked Questions

Does a fractional CFO need to be based in London?

Not necessarily. Most fractional CFO work is done remotely. However, a London-based CFO understands the local investor ecosystem, UK tax incentives like EIS/SEIS and R&D credits, and Companies House requirements better than an overseas alternative.

How quickly can a fractional CFO get up to speed?

At ScaleWithCFO, the first 30 days are dedicated to understanding your business, cleaning up financial data, and establishing the reporting baseline. Most founders feel the impact within the first month.

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