Interim CFO | B2B SaaS Scale-Up | London

Harmonic Finance™ | Certified B Corp; Greater London; Hybrid; GBP 185,000 - 277,000; Part time

Job summary

Harmonic appoints an Interim CFO for a six-month engagement to lead the finance function end-to-end in a London-based B2B SaaS scale-up. You will report to the CEO and work with the board and investors, combining strategic direction with hands-on delivery.

As the senior finance leader, you will own forecasting, budgeting, cash management, controls, and monthly investor reporting, while partnering with the leadership team on strategic initiatives. Hybrid London location.

Qualifications

• Qualified accountant (ACA, ACCA or CIMA) or equivalent.
• Experience as CFO or senior Finance Director in a SaaS/tech business.
• Proven board/investor reporting experience in PE/VC-backed environments.
• Strong grasp of SaaS metrics, revenue recognition and subscription models.
• Able to step in quickly and deliver in an interim capacity.
• Multi-entity or international group experience.
• Exposure to fundraising, refinancing or exit processes.

Responsibilities

• Lead the finance function and act as the senior financial partner to the CEO and leadership team.
• Own board and investor reporting, including monthly packs and SaaS KPIs (ARR, NRR, churn, CAC payback).
• Lead budgeting, forecasting and long-range planning, and monitor cash runway.
• Review and strengthen financial controls, processes and systems to scale.
• Oversee year-end audit, statutory reporting and tax compliance across entities.
• Support fundraising, debt or M&A activity, including investor relations and due diligence.
• Manage and develop the finance team, and decide long-term needs of the function.
• Track record of board reporting in PE/VC-backed environments.
• Ensure compliance with revenue recognition for SaaS and subscription models.
• Operate in an interim capacity with cross-functional collaboration.

Skills

SaaS finance leadership

Education

Professional accounting qualification (ACA/ACCA/CIMA)

Job description

Interim CFO | B2B SaaS Scale-Up | London

Harmonic is pleased to be working exclusively with a B2B SaaS scale-up to appoint an Interim CFO for an initial six-month engagement.

The Client

A B2B SaaS scale-up selling software to enterprise customers. The business is backed by renowned investors and led by a strong, experienced senior leadership team. It has a growing international customer base and is now building out the finance function to support its next stage of growth.

The Role

This is a six-month interim engagement for an experienced CFO. You’ll report to the CEO and work closely with the board and investors. You’ll own the finance function end to end, covering reporting, planning, cash and governance, and you’ll act as a commercial partner to the leadership team. The role is both strategic and hands-on: you’ll set direction while staying close enough to the detail.

Key Responsibilities

• Lead the finance function and act as the senior financial partner to the CEO and leadership team
• Own board and investor reporting, including monthly packs and SaaS KPIs (ARR, NRR, churn, CAC payback)
• Lead budgeting, forecasting and long-range planning, and keep a close eye on cash runway
• Review and strengthen financial controls, processes and systems so they can scale
• Oversee the year-end audit, statutory reporting and tax compliance across entities
• Support any fundraising, debt or M&A activity, including investor relations and due diligence
• Manage and develop the finance team, and assess what the function will need long term
• Qualified accountant (ACA, ACCA or CIMA) or equivalent
• Previous CFO or senior Finance Director experience in a SaaS or technology business
• Track record of board and investor reporting in a PE or VC-backed environment
• Strong grasp of SaaS metrics, revenue recognition and subscription models
• Able to step in quickly and deliver in an interim capacity
• Multi-entity or international group experience
• Exposure to fundraising, refinancing or exit processes

Package

Day Rate: £1,000-1,500 per day (IR35 status to be confirmed)

Location: London (Hybrid)

Start Date: ASAP

At Harmonic, we are dedicated to fostering an inclusive and equitable workplace. We actively welcome applications from individuals of all backgrounds and assure you that every candidate will be thoughtfully considered for the roles we represent, without regard to race, religion, gender expression, disability, or sexual orientation.