Senior Internal Auditor

As a Senior Internal Auditor, you’ll lead audits and assurance projects that strengthen Thames Water’s controls and risk management. You’ll drive best practices, support audit improvements, and build strong stakeholder relationships—enhancing the impact and visibility of the internal audit team.

We’re looking for a proactive and driven Senior Internal Auditor to join our Internal Audit team at Thames Water on a 12 month fixed term contract, with a possible permanent opportunity on offer for the successful candidate. This is a fantastic chance to lead high-impact audits, influence senior stakeholders, and help shape the future of risk and assurance across the business. 

You’ll be part of a collaborative and forward-thinking team, delivering audits that make a real difference—enhancing controls, improving processes, and supporting strategic decision-making. If you’re passionate about audit excellence and want to work in a role where your insights matter, we’d love to hear from you.

What you will be doing as Senior Internal Auditor

• Lead and deliver impactful audits across compliance, financial, operational, programme, and technology areas—driving high-quality outcomes from planning through to final reporting. Collaborate with stakeholders at all levels, including Directors, to ensure findings are clear, risk-aligned, and actionable.
• Ensure audit findings are robust and meaningful, with risks clearly assessed and remediation timelines agreed with business owners. Maintain high standards of audit quality in line with internal policies and professional guidelines.
• Build strong relationships across the business, working closely with auditees and stakeholders to support action closure, share insights, and promote a culture of continuous improvement.
• Identify opportunities to enhance processes and controls, ensuring audits deliver real value and support cost-effective, efficient operations.
• Support the Audit Manager in developing audit methodologies, tools, and reporting frameworks that strengthen the team’s effectiveness and consistency.
• Provide expert advice and business insight, contributing to a high-performing audit function and offering practical solutions to risk and control challenges.
• Collaborate across the Risk, Audit and Assurance team, helping to raise the profile of internal audit and drive improvements in risk management and governance.
• Offer ad hoc support on risk and control matters, acting as a trusted advisor to the business when needed.
• Stay ahead of industry best practices, bringing fresh thinking and innovative tools to enhance audit delivery and team performance.

What you should bring to the role

• A relevant professional qualification (e.g. ACA, ACCA, CIMA, CMIIA, CIA)
• Extensive experience of internal audit 
• Proven track record of delivering end-to-end audits, preferably including large infrastructure or asset-based projects
• Strong stakeholder engagement skills, with experience reporting to senior management
• Analytical mindset with the ability to challenge and improve existing processes
• Confident communicator with the ability to influence without formal authority
• Objective, detail-oriented, and committed to delivering high-quality work

Location– Hybrid, flexible working, Reading.

What’s in it for you? 
An opportunity to join a company that offers its employees a rewarding career path, allowing individuals to reach their full potential. This is an exciting time to join Thames Water as we continue to deliver our innovative turnaround plan.

• Competitive salary of £55,000 - £70,000 per annum, depending on experience.
• Annual Leave - 26 days holiday per year, increasing to 30 with the length of service. (Plus bank holidays) 
• Contributory pension – Defined Contribution - Maximum of 12% -2x employee contribution.
• Personal Medical Assessments – Open to all once a year.
• Performance-related pay plan directly linked to company performance measures and targets
• Access to lots of benefits to help you take care of your and your family’s health and well-being, and your finances – from annual health MOTs and access to physiotherapy and counselling, to Cycle to Work schemes, shopping vouchers and life assurance.

Find out more about our benefits and perks

Who are we?
We’re the UK’s largest water and wastewater company, with more than 16 million customers relying on us every day to supply water for their taps and toilets. We want to build a better future for all, helping our customers, communities, people, and the planet to thrive. It’s a big job and we’ve got a long way to go, so we need help from passionate and skilled people, committed to making a difference and getting us to where we want to be in the years and decades to come.

Learn more about our purpose and values

Working at Thames Water
Thames Water is a unique, rewarding, and diverse place to work, where every day you can make a difference, yet no day is the same. As part of our family, you’ll enjoy meaningful career opportunities, flexible working arrangements and excellent benefits.
If you’re looking for a sustainable and successful career where you can make a daily difference to millions of people’s lives while helping to protect the world of water for future generations, we’ll be here to support you every step of the way. Together, we can build a better future for our customers, our region, and our planet.

Real purpose, real support, real opportunities. Come and join the Thames Water family. Why choose us? Learn more.

We’re committed to being a great, diverse, and inclusive place to work. We welcome applications from everyone and want to ensure you feel supported throughout the recruitment process. If you need any adjustments, whether that’s extra time, accessible formats, or anything else just let us know, we’re here to help and support.

When a crisis happens, we all rally around to support our customers. As part of Team Thames, you’ll have the opportunity to sign up to support our customers on the frontline as an ambassador. Full training will be given for what is undoubtedly an incredibly rewarding experience. It’s also a great opportunity to learn more about our business and meet colleagues.

Disclaimer: due to the high volume of applications we receive, we may close the advert earlier than the advertised date, so we encourage you to apply as soon as possible to avoid disappointment.