RES

AP & Treasury Manager, Asset Management Finance

Join RES in Kings Langley as an AP & Treasury Manager overseeing accounts payable and treasury for renewable energy assets. Lead a finance team, manage banking operations, and support system improvements. Enjoy a diverse, inclusive workplace with growth opportunities and a competitive benefits package.
RES
RES
Kings Langley, United Kingdom On-site Contract position UTC+00:00

RES

Company Overview

Name

Renewable Energy Systems (RES)

Headquarters

Hertfordshire, United Kingdom

Founded

1981

Size

Approximately 2,500 employees globally (source: linkedin.com). No publicly disclosed revenue figures for 2023.

What They Do

RES focuses on a diverse range of renewable energy technologies, including wind (both onshore and offshore), solar photovoltaic (PV), battery energy storage systems (BESS), and green hydrogen solutions. The company provides comprehensive services that span the entire lifecycle of renewable energy projects, from initial development and engineering to construction, operations and maintenance (O&M), asset management, and financing. Their expertise allows them to deliver utility-scale projects that meet the growing demand for sustainable energy solutions across various markets, including utilities, corporates, and governments (source: res-group.com).

Projects & Track Record

RES has an impressive portfolio of completed projects, including the 278MW King Mountain Wind Farm in Texas, which was completed in 2001 and was the world's largest at the time. Other notable projects include the 90MW Inner Dowsing offshore wind farm in the UK and the 270MW Lincs offshore wind farm, both of which have contributed to RES's reputation as a leader in the renewable energy sector. The company has also developed significant solar projects, such as the 30MW Webberville solar park in Texas, showcasing its versatility in renewable energy solutions (source: res-group.com).

Recent Developments

In recent years, RES has made significant strides in expanding its project portfolio and capabilities. In 2024, the company secured a Generation License for the 70MW Elmacık Wind Power Plant in Turkey and advanced the development approval for the Tarong West Wind Farm in Queensland, Australia, which is set to provide power for approximately 230,000 homes. Additionally, RES has partnered with Octopus Energy on a £3 billion investment in green hydrogen in the UK, further solidifying its commitment to innovative renewable energy solutions (source: keyfactsenergy.com).

Working There

RES offers a variety of roles across multiple departments, including development, engineering, construction, operations and maintenance, asset management, finance, and legal services. The company emphasizes a collaborative culture, with a commitment to diversity and inclusion, and provides a stimulating work environment for its employees. The global headquarters in Kings Langley, UK, features modern facilities designed to support employee well-being, such as bike racks and showers, promoting a healthy work-life balance (source: res-group.com).


Last updated on Feb 23, 2026 | Report an issue

Job Description

We're the world's largest independent renewable energy company. We're guided by a simple yet powerful vision: to create a future where everyone has access to affordable, zero carbon energy.

We know that achieving our ambitions would be impossible without our people. Because we're tackling some of the world's toughest problems, we need the very best people to help us. They're our most important asset so that's why we continually invest in them.

RES is a family with a diverse workforce, and we are dedicated to the personal professional growth of our people, no matter what stage of their career they're at. We can promise you rewarding work which makes a real impact, the chance to learn from inspiring colleagues from across a growing, global network and opportunities to grow personally and professionally.

Our competitive package offers a wide range of benefits and rewards.

The position

Reporting to: Finance Manager - Process Improvements, Finance Asset Management dotted line to Client Finance Managers

Location: Kings Langley office. Responsible for AP and treasury operations for assigned client portfolio.

Team managed: 3-5 AP & Treasury professionals. Scope to expand to 7-8 based on portfolio complexity and business growth.

The AP & Treasury Manager is responsible for leading the AP and treasury function for an assigned portfolio of renewable energy asset management clients within the FAM Northern Europe team. The role carries full end-to-end accountability for accounts payable, banking and treasury operations, IFS power-user support, and team management.

Dual-cover capability is a core requirement. The individual will develop working knowledge of the other AP & Treasury Manager's portfolio, clients, and banking relationships within a reasonable timeframe.

Please note that this role is being offered on a 12-month fixed term contract basis.

Organisational context

The FAM Northern Europe team acts as an outsourced finance business partner, delivering financial support services under Management Service Agreements (MSAs) to clients owning renewable energy assets across onshore wind, solar, storage and hydro. The department currently manages over 200 legal entities across 17 clients and three regions (UK & Ireland, Nordics and Germany).

The team's scope includes:

  • Purchase Ledger: >22,500 invoices per annum
  • Banking: 300 bank accounts
  • Treasury: cash processing, banking platform management and bank mandate administration
  • IFS super-user support
  • Business user support for Accounts Payable transactions
  • Month end, quarter end and year end processing to agreed deadlines

Key accountabilities

Team Leadership & Management

  • Lead, manage and develop a team of AP & Treasury professionals, setting clear expectations and supporting professional growth
  • Allocate and monitor clerk workload to ensure even distribution and timely delivery across all assigned clients
  • Act as first escalation point for all AP and treasury issues within the portfolio
  • Conduct regular one-to-ones and performance conversations with direct reports
  • Support the onboarding and training of new team members within the portfolio
  • Maintain a regular contact with Client Leads and other AP & Treasury Manager.
  • Support and cover the wider FAM NE team as required, including providing substantive cover for the other AP & Treasury Manager during absences or peak periods
  • Manage team absence and absence records and pull together cover plans to ensure smooth running of portfolio

Accounts Payable

  • Own the end-to-end AP process for all assigned clients, from invoice receipt through to payment and reconciliation
  • Ensure all supplier invoices are processed accurately, correctly coded and posted on time (both PO and non-PO)
  • Manage payment proposals and oversee payment run processes, ensuring dual-control requirements are met at every stage
  • Act as primary escalation for supplier queries, approval workflow delays and invoice disputes
  • Oversee the processing of urgent and manual payments, ensuring appropriate approvals and documentation are in place
  • Maintain supplier master data integrity; Ensure AP team are independently verifying any supplier bank detail changes before they are applied
  • Support month-end, quarter-end and year-end close to agreed deadlines
  • Spot-check invoice coding quality regularly and provide feedback to clerks
  • Built in and agree robust Payment runs cycles and agree and communicate actively with the clients and business to minimise the urgent payment runs.
  • Regularly review the POAs and creditors ledger ensuring creditors balances are kept clean and up to date.
  • Manage out of system payments such as distributions, loan repayments & VAT payments
  • Carry out bank approval of intercompany transfers.

Treasury & Banking

  • Own the treasury matrix and bank mandate register for all cluster clients, ensuring it is accurate and reviewed monthly
  • Act as primary contact with banks for mandate changes, signatory updates and approval limit amendments.
  • Effectively implement and manage the bank access for every client account so there are appropriate number of individuals for cover.
  • Oversee bank uploads and payment approvals, ensuring dual-signatory controls are applied before any payment is released
  • Oversee daily bank reconciliations across all cluster entities; resolve discrepancies promptly and escalate aged items
  • Oversee cash postings across all cluster bank accounts
  • Conduct and document quarterly bank access reviews, confirming all access rights are current and appropriate
  • Maintain the letter tracker for all bank correspondence and ensure follow-ups are completed

IFS & Systems Administration

  • Act as a power user within the IFS system, supporting team members on system operations, troubleshooting and process optimisation
  • Collaborate with the IFS team on testing, training, and system improvements; escalate complex system issues for resolution
  • Contribute to continuous improvement initiatives within the team and across the wider department.

Client & Stakeholder Management

  • Act as primary client contact for AP and treasury matters across all assigned clients
  • Build and maintain strong, trust-based client relationships; attend client calls and reviews as required
  • Communicate proactively on issues, process changes and service updates
  • Manage multiple client priorities simultaneously without compromising quality or timelines
  • Represent the FAM NE team professionally at all levels of seniority, internally and externally

Controls & Compliance

  • Ensure all AP and treasury controls always operate effectively within the portfolio
  • Maintain up-to-date process documentation for every assigned client - one standardised framework with client-specific appendices
  • Enforce fraud prevention controls, particularly around supplier bank detail changes and payment authorisation
  • Support internal and external audit requests; ensure the cluster is always audit-ready
  • Identify and escalate control weaknesses to the Head of FAM NE

Knowledge & Skills

  • Strong working knowledge of accounts payable, purchase ledger and treasury operations
  • Hands-on experience with banking platforms, mandate management and payment authorisation frameworks
  • Proficient in IFS or equivalent ERP system with exposure to contributing to system improvements.
  • Confident navigating multi-entity environments
  • Experience managing high-volume AP portfolios, ideally 50+ entities
  • Ability to lead and develop a small finance team, allocating work effectively and maintaining quality standards
  • Excellent attention to detail with a track record of delivering accurate, timely work under pressure
  • Strong client relationship skills - confident communicating at all levels of seniority, including with external clients and banks
  • Ability to manage competing priorities across a complex, multi-entity portfolio
  • Proactive approach to identifying and resolving problems; comfortable escalating when necessary
  • Comfortable working with large data sets

Experience & Qualifications

  • Significant experience in a transactional finance role, ideally within asset management, financial services or an outsourced finance environment
  • Proven experience managing or supervising a small finance team
  • Demonstrated experience with treasury and banking operations, including bank mandate administration
  • IFS (or equivalent ERP) system knowledge with a solid understanding of system controls and access management
  • Experience managing a high-volume, multi-entity AP portfolio (50+ entities desirable)
  • Recognised accountancy qualification (e.g. AAT, part-qualified ACCA/CIMA or equivalent)

At RES we celebrate difference as we know it makes our company a great place to work. Encouraging applicants with different backgrounds, ideas and points of view, we create teams who work together to solve complex problems and design practical solutions for our clients. Our multiple perspectives come from many sources including the diverse ethnicity, culture, gender, nationality, age, sex, sexual orientation, gender identity and expression, disability, marital status, parental status, education, social background and life experience of our people.

Apply now

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About the role

August 19, 2026

August 19, 2026

Contract position

On-site

Company

Solar Energy, Wind Energy, Hydropower, Energy Storage

RES

res-group.com

  •  Kings Langley, United Kingdom

Significant experience in a transactional finance role, ideally within asset management or financial services.

UTC+00:00