Interim Financial Controller | International SaaS Scale-Up

Harmonic are delighted to be partnering exclusively with a rapidly scaling SaaS business in their search for an experienced Interim Financial Controller on a contract basis. Having grown significantly over the past 12 months, the business is entering a critical next phase of scale and is looking to build a robust, high-performing finance function to support continued international expansion.

This role will suit a hands-on finance professional who thrives in high-growth environments, enjoys building structure from first principles, and is comfortable taking ownership of core finance operations while driving transformation and automation.

The Role

Reporting directly into senior leadership, you will take responsibility for establishing the financial control framework and day-to-day finance operations. You’ll lead improvements across month-end, controls, compliance, and reporting, while helping to build a scalable finance infrastructure that supports rapid growth.

Key Responsibilities

• Lead and manage the month-end close, ensuring timely and accurate management reporting, journals, accruals, and reconciliations.
• Build and strengthen the financial control environment, implementing robust accounting processes and governance.
• Take ownership of AP and AR processes, improving workflows and introducing automation where possible.
• Support the selection and implementation of a new ERP system, helping establish scalable finance processes.
• Oversee statutory compliance across multiple jurisdictions, including local tax and regulatory requirements.
• Support the design and management of transfer pricing processes and intercompany structures.
• Drive improvements across reporting, systems, and finance operations to support continued international scale.
• Partner closely with leadership to provide financial insight, prioritisation support, and operational rigour.
• Help build out the wider finance team structure as the business grows.
• Provide ad-hoc support across strategic finance projects as required.

What We Need to See (Essential)

• Experienced accountant with strong technical capability and a proven track record in high-growth environments.
• Experience building or transforming finance functions within scaling businesses.
• Strong understanding of financial controls, compliance, and multi-entity operations.
• Experience with ERP implementations or major finance systems upgrades.
• Exposure to international businesses with multiple countries / entities.

What we’d like to see (bonus)

• Ideally experience within a VC Backed SaaS, technology business.

Day Rate: £550-£650 per day

Contract Length: 6-9 months

Start Date: ASAP

Location: London / Hybrid

If you are interested – to be considered for the role please forward your CV to ed.naish@harmonicfinance.com

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.