Senior Financial Accountant London, United Kingdom

PhysicsX is a deep-tech company with roots in numerical physics and Formula One, dedicated to accelerating hardware innovation at the speed of software. We are building an AI-driven simulation software stack for engineering and manufacturing across advanced industries. By enabling high-fidelity, multi-physics simulation through AI inference across the entire engineering lifecycle, PhysicsX unlocks new levels of optimization and automation in design, manufacturing, and operations — empowering engineers to push the boundaries of possibility. Our customers include leading innovators in Aerospace & Defense, Materials, Energy, Semiconductors, and Automotive.

The Opportunity

PhysicsX is looking for a Senior Financial Accountant to join our growing finance team. This is a technically demanding role for a qualified accountant who is confident working across complex, multi-entity, multi-jurisdiction accounting — and who wants to take genuine ownership of the processes they run. You’ll be a key part of a team of four, reporting directly to the Finance Manager, and acting as the point of contact for group tax and statutory reporting across our UK, US, and Singapore entities. You’ll work closely with external tax consultants, auditors, and advisers, and be expected to take clear ownership of the workstreams you lead. This is a role for someone who thrives on responsibility, brings fresh thinking to improve processes and controls, and has the technical depth to navigate regulatory complexity across multiple jurisdictions.

What You’ll Do

• Revenue recognition: Leading global revenue recognition in line with FRS 102, ensuring accuracy and consistency with Group accounting policies across all entities.
• Tax compliance and advisory: Supporting group tax compliance across the UK, US, and Singapore — acting as the main point of contact between the business and our external tax advisers, and helping to ensure corporation tax returns and year-end filings, including federal, state, and local obligations, are completed accurately and on time. Managing VAT and GST compliance obligations across jurisdictions. Supporting R&D tax credit claims in collaboration with specialist advisers.
• Accounts receivable: Owning the AR function end-to-end — including customer invoicing, cash allocation, and credit control — ensuring timely and accurate processing.
• Technical Accounting & Standards: Maintaining compliance with complex accounting standards across the group, including lease accounting (IFRS 16) and share-based payments (IFRS 2). Assessing and implementing new or amended standards as they come into effect, ensuring Group accounting policies remain current and consistent. Acting as the internal point of reference for technical accounting queries across the business.
• Statutory and regulatory reporting: Leading timely and accurate statutory and regulatory reporting across the group, ensuring compliance with IFRS, UK GAAP, and relevant local standards. Providing audit support.
• Controls and process improvement: Building and evolving a robust but agile financial controls framework — strong enough for scale and audit-readiness, without slowing the business down. Partnering with the wider organisation to embed smarter financial processes, helping teams understand and adopt improved ways of working. Identifying and implementing process improvements to strengthen controls, efficiency, and reporting quality.

What Makes a Great Candidate

• A qualified accountant (ACA or ACCA) with at least four to five years of relevant post-qualification experience.
• Strong technical accounting knowledge — you're confident with IFRS, UK GAAP, and comfortable navigating multi-jurisdiction regulatory requirements.
• Demonstrable experience across tax compliance, revenue recognition, and statutory reporting — you'll be expected to bring technical confidence to these areas from day one.
• Experience in a technology, engineering, SaaS or high-growth start-up environment.
• Accurate and detail-oriented — you take pride in getting things right and spot inconsistencies others might miss.
• Able to own and execute workstreams independently, while working collaboratively as part of a team.
• Excellent organisational and time management skills — you prioritise effectively, manage competing demands, and consistently deliver to deadline.
• A proactive communicator — with both internal stakeholders and external advisers — who flags issues early and knows when to elevate.
• Comfortable in a fast-moving, high-growth environment where the landscape is constantly evolving.

Contract: Permanent, full-time

Location: London - hybrid, with 3 days per week in the office

Reports to: Finance Manager

What We Offer

• Build what actually matters: Help shape an AI-native engineering company at a formative stage, tackling problems that genuinely matter for industry and society. This is work with real-world impact - and something you can be proud to stand behind.
• Learn alongside exceptional people: Work with a high-caliber, collaborative team of engineers, scientists, and operators who care deeply about doing great work, and about helping each other get better.
• Influence over hierarchy: We operate with a flat structure: good ideas win- wherever they come from. Questioning assumptions and challenging the status quo isn’t just welcomed, it’s expected.
• Building meaningful technology is a marathon, not a sprint. We believe in balancing focused, ambitious work with a life beyond it.
• Equity options - share meaningfully in the company you’re helping to build.
• 10% employer pension contribution - because investing in future matters.
• Free office lunches - to keep you energised and focused.
• Enhanced parental leave - 3 months full pay paternity and 6 months full pay maternity leave, to provide extra flexibility during the moments that matter most.
• YellowNest nursery scheme - to help working parents manage childcare costs.
• 25 days of Annual Leave (+ Public Holidays) - because taking time to rest matters.
• Private medical insurance - 100% employee cover, giving you complete peace of mind.
• Wellhub Subscription - gain access to thousands of gyms, classes and wellness apps, supporting both physical and mental wellbeing.
• Eye tests - because good work depends on good health.
• Personal development - dedicated support for learning, development, and leveling up over time.
• Employee Assistance Programme (EAP) - confidential wellbeing support, available whenever you need it.
• Bike2Work scheme and Season ticket loan - to make getting to work easier and greener.
• Octopus EV salary sacrifice - for a simpler, more sustainable way to drive electric.

We value diversity and are committed to equal employment opportunity regardless of sex, race, religion, ethnicity, nationality, disability, age, sexual orientation or gender identity. We strongly encourage individuals from groups traditionally underrepresented in tech to apply.