Accounting Director | Accountancy Built for Start-Ups | London

Accounting Director | Tech-First Accountancy for Start-Ups | London The Client Harmonic are delighted to be partnering with a technology-led accountancy business that has built its product and service model specifically for the UK start-up ecosystem (Pre Seed to Series A). Unlike traditional practices, this company embeds a large in-house engineering team directly alongside its accountants, using AI and software to give its directors far greater leverage than is possible in a conventional firm. Founded by entrepreneurs with a proven track record of building and exiting technology companies, the business is at an early but well-capitalised stage of its growth. The culture is direct and meritocratic - progression is uncapped and tied to performance. For the right person, this is a ground-floor opportunity to grow with a business that has strong commercial momentum and a product that business leaders and Founders genuinely value. The Role Reporting directly to the CEO, you will be expected to build strong, trusted relationships with founders and senior teams across your portfolio. The Accounting Director will own a high-volume portfolio of fast-growing start-up clients across the UK and US, acting as their primary point of contact for all accounting, compliance, and advisory needs. You will cover the full spectrum of start-up finance - statutory accounts, VAT, corporate and employment tax, R&D tax credits, S/EIS, financial modelling, and valuations for share schemes and fundraising rounds. What makes this role distinct is the technology dimension. You will work directly alongside the in-house engineering team, identifying workflow inefficiencies and contributing to the development and rollout of AI-driven automation tools for your team and clients. This is not a role for someone who wants to do traditional accounting in a traditional way - it is for someone genuinely excited by the start-up world, interested in where accounting and technology intersect, and ready to work in a fast-moving, high-ownership environment. Key Responsibilities • Manage a high-volume portfolio of fast-growing start-up clients across the UK and US, acting as primary point of contact throughout the relationship • Deliver the full range of accounting and compliance services, including bookkeeping, VAT, corporate tax, payroll, and statutory accounts • Advise clients on start-up-specific tax matters including R&D tax credits, S/EIS, employment tax, and corporate tax • Support clients through fundraising rounds, including financial modelling, budgeting, and valuations for share schemes and investment rounds • Identify workflow inefficiencies and collaborate with the engineering team to scope and roll out automation solutions • Onboard new clients and manage the full client lifecycle from initial engagement through to ongoing advisory • Contribute to the growth and development of the wider accounting team Essential Experience • ACA qualified (or equivalent), ideally with 2-4 years' post-qualification experience at Manager level • Background in a Big 4 firm or large to mid-sized accountancy practice • Strong technical accounting and tax knowledge across a broad range of areas • Genuinely interested in the start-up ecosystem and motivated to join an early-stage business • Comfortable managing a high-volume client portfolio at pace, with sound judgement on when to act and when to escalate • Strong communicator, able to build credibility quickly with founders and senior stakeholders Desirable Experience • Experience advising start-up or scale-up clients on R&D, S/EIS, or fundraising-related matters • Exposure to tech-enabled workflows or interest in how AI is changing the accounting profession Package • Salary: £75,000 - £80,000 • Location: Victoria, London - office-based (5 days per week, with some flexibility for senior hires) • Start Date: ASAP / flexible 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.