Management Accountant | B2B SaaS Startup | London, Hybrid The Client Harmonic is delighted to be exclusively partnering with a B2B SaaS start-up that has grown their top tier customer base 8x in the last year, with a clear target to double it again by the end of next year. Having closed multiple funding rounds in quick succession, the business is well-capitalised and growing fast, with further investment expected on the horizon. The finance function is intentionally lean: this hire will work directly with the senior finance leader and take on meaningful ownership from day one, with a clear path to accelerating their career in a short period of time. The Role Reporting directly into the VP Finance (who is a strong mentor and committed to investing in this person's development), the Management Accountant will own core accounting and billing operations across a three-entity structure spanning the UK and multiple US states. Day-to-day, this means preparing consolidated management accounts, overseeing outsourced bookkeeping (UK and US), managing complex usage-based billing reconciliation, and owning AP/AR and compliance processes. The business operates in an AI-first way and welcomes new thinking on process and tooling: this is a role for someone who enjoys building and improving, not just maintaining. Longer-term, there is genuine scope to own the entire finance function as the company continues to scale. Key Responsibilities Prepare and consolidate monthly management accounts across three legal entities (UK and multiple US states) Perform monthly billing reconciliation across usage-based data, third-party invoices, and internal reporting Oversee outsourced bookkeeping providers in both the UK and US, with the option to bring processes in-house over time Own AP/AR processes, including invoicing, monitoring outstanding balances and collections Manage intercompany transactions across the multi-entity structure Support quarterly and annual compliance and tax filings across UK and US jurisdictions, including multi-state US filings Identify process inefficiencies and rebuild workflows, including through AI and tooling where appropriate Contribute to month-end close, including journal preparation, reconciliations and source data validation Essential Experience Newly qualified accountant (ACA/ACCA/CIMA/AAT) or near-qualified with strong momentum towards completion 0-2 years of post-qualification experience, or equivalent in a comparable role Background in a B2B SaaS or technology business, or in practice with a strong technology client portfolio Comfortable operating with autonomy in a small team, with the ability to build processes rather than inherit them Strong analytical skills with the ability to manage and interpret complex data sets Desirable Experience Exposure to multi-entity or multi-jurisdiction accounting structures, particularly UK and US Experience with Xero or comparable accounting software Familiarity with billing systems or usage-based revenue models Salary: £50,000-£55,000 equity Location: London (Farringdon), hybrid (2-3 days in office per week) Start Date: Flexible; preference for 1 month notice, open to longer for the right candidate 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.