Finance Assistant

Type: Full-time 

Salary Range:  £30,000-35,000

What We Do

At Heat Geek, we are tackling one of the UK’s biggest carbon contributors: home heating. 20% of all UK carbon emissions stems from home heating  – and that contribution is even bigger on a global scale. At Heat Geek, we are changing that. By simplifying a traditionally complex industry and revolutionising the technology used by installers, we’re making low-carbon heating mainstream. We are on track to prevent 1,000,000 kg of carbon from entering our atmosphere in Q1 of 2026, and we won’t stop there!

Join Us!

People are at the core of who we are and what we do. From decreasing homeowners’ energy bills to help with the cost of living, to empowering talented heating engineers to perform outstanding installations, to ensuring a greener world for all of us, we believe in the power of what we can all do together. – And we need passionate, talented, hard working people to be a part of this journey. 

Your Mission

Our Heat Geek crew is excited to bring a Finance Assistant into the team. In this role, you’ll help keep the financial engine of the business running smoothly as we scale. From processing transactions and keeping records accurate, to supporting reporting and helping improve the way we work, you’ll bring structure, precision, and reliability to a fast-moving climate tech business.

This is a role for someone who loves getting the details right, takes pride in building order from complexity, and wants their work to contribute to something bigger: helping make low-carbon heating mainstream

If you’re reading this and it resonates, we know you could do this job anywhere — but we want you to do it HERE, with us, because we need persevering teammates who care deeply about making a real difference in the world.

Role Outputs

• Raise invoices, self-billed invoices and credit notes


• Bank and grant reconciliations


• Expense processing


• Supplier inbox monitoring across multiple entities


• Supplier payment run scheduling and payment variations


• Referral fee processing


• Supplier rebate claims


• Platform subscription monitoring and chasing payments


• Installer finance onboarding


• Month-end support


• Regular reporting (e.g. weekly management reports)


• Finance process documentation


• Finance bot training (internal AI tooling)


• Management of international learning receipts


• Ad hoc support across people ops and hardware requests

Candidate Requirements

• 1-2 years experience in a finance admin or accounts assistant role 


• Working towards or holds AAT or similar financial qualification 


• Comfortable with high-volume, process-driven work


• Organised, reliable, and able to manage competing deadlines


• Happy working in a fast-paced startup environment


• Strong attention to detail


• Able to attend office in Waterloo 3 days a week

It’s a bonus if you have…

• Experience using Xero

We believe great teams are built from different ways of thinking, learning, and living, and as such, we strive to build an organisation where people can show up as themselves. – Even if you don’t tick every box listed above, but are passionate about the work that we are doing and believe that you can make a positive impact here, we’d love to hear from you. So please drop us a message or share more detail in your application!

Ways of Working + Benefits

This is a 3-day-in-the-office hybrid role where you will work with the team at our office in Sustainable Ventures in Waterloo, Europe's biggest climate tech hub. It's a 5-minute walk from Waterloo Station and an energising space for anyone working on climate change. And don’t get us started on the epic view!

Some of our measurable benefits include:

• £5,000 contribution towards your own heat pump installation


• Shares in the company, allocated under a tax-incentivised scheme


• Salary that’s evaluated regularly, and based on skills, impact, and role scope—not negotiation tactics


• Private medical & dental insurance


• Learning and development budget 


• Annual summer retreat


• Gym membership contribution 


• Season ticket loan


• Cycle to work scheme


• Yoga, run club and social events with other sustainability startups in our co-working space

…alongside monthly socials and regular collaboration opportunities with a team that’s passionate, hardworking, and kind.