At Amentum, we're not just solving problems; we're engineering the future. Our team is driven by an unyielding commitment to innovation, integrity, and collaboration, tackling some of the most significant challenges in science, security, and sustainability. If you're passionate about making a real impact and want to be part of a community that values ethical excellence, this is the place where your ambition can thrive.
Here, we believe that success comes from continuously pushing boundaries and working together to deliver on our promises. We embrace challenges with confidence and are dedicated to creating a secure and vibrant future for all.
We’ll inspire and empower you to deliver your best work so you can evolve, grow and succeed – today and into tomorrow. We offer an exciting range of opportunities to develop your career within a supportive team who always strive to do the right thing for our people, clients and communities.
People are our greatest asset, and we offer a competitive package to retain and attract the best talent.
In addition to the benefits you’d expect, UK employees also receive free single medical cover and digital GP service, family-friendly benefits such as enhanced parental leave pay and free membership of employee assistance and parental programmes, plus reimbursement towards relevant professional development and memberships.
Work-life balance and flexibility is a key focus area for us. We’re happy to discuss hybrid, part-time and flexible working hours, patterns and locations to suit you and our business.
About the Opportunity
The Office Administrator plays a central role in ensuring the smooth, safe, and efficient day-to-day operation of the Harwell office. This is a broad and hands-on role combining responsibilities across office administration, reception, and facilities coordination.
The position sits at the heart of the office environment, acting as a key point of contact for employees, visitors, and service providers. You will take ownership of maintaining a professional, compliant, and well-functioning workplace, enabling staff to focus on their core work.
This role requires a highly organised and proactive individual who can manage a varied workload, respond to changing priorities, and continuously improve office systems and processes.
Key Responsibilities
Office Administration & Reception
Act as front-of-house, welcoming visitors and providing a professional first impression of the office.
Manage incoming and outgoing post, deliveries, and courier services.
Coordinate meeting rooms, including bookings, AV setup, and catering arrangements.
Maintain office supplies, ensuring availability of stationery, kitchen items, and consumables.
Ensure the office remains tidy, organised, and presentable at all times.
Manage incoming communications (email, phone, Teams), triaging and responding where appropriate.
Support staff with day-to-day administrative requests.
Maintain office records, systems, and documentation to support efficient operations.
Facilities & Office Operations
Act as the primary point of contact for office and facilities-related issues.
Provide administrative support to the Laboratory Services Manager for the laboratory facilities at Harwell and Culham.
Liaise with landlords, buildings management, and service providers to resolve issues promptly.
Coordinate contractors on-site (office only), ensuring compliance with EHSSS (Environment, Health, Safety, Security, Sustainability) requirements, Risk Assessments, Method Statements, and permits.
Plan and oversee scheduled and reactive maintenance activities, tracking actions through to completion.
Maintain office equipment (printers, access systems, meeting room technology) and arrange repairs or replacements.
Support supplier and vendor management, including performance monitoring and renewals.
Assist with procurement activities, including raising purchase requests and processing invoices for the office and lab facilities at Harwell and Culham.
Contribute to the continuous improvement of office systems, processes, and ways of working.
Health, Safety, Security & Compliance
Support compliance with EHSSS, and company policies and procedures.
Coordinate fire warden and first aider training, ensuring appropriate coverage.
Ensure first aid kits, emergency equipment, and safety systems are regularly checked and maintained.
Maintain accurate and up-to-date records (risk assessments, COSHH, safety documentation).
Support internal and external audits (EHSSS, quality, information security), tracking actions to completion.
Assist with incident reporting, EHSSS observations, and follow-up actions.
Support business continuity and emergency preparedness activities where required.
Office Coordination & Support
Manage visitor access, building inductions, and security processes
Support onboarding of new starters, including inductions and access arrangements.
Coordinate internal communications, office updates, and notices.
Organise meetings, events, and social activities.
Support time recording processes and general business administration.
Act as a key support interface for functions such as HR, EHSSS, IT, and Security.
Key Skills and Experience
Proficient in Microsoft Office (Outlook, Teams, Word, Excel).
Strong organisational and time management skills, with the ability to prioritise competing demands.
Proactive and flexible approach, with a willingness to take ownership
High attention to detail and commitment to quality.
Strong written and verbal communication skills, with the ability to engage stakeholders at all levels.
Ability to work independently and respond effectively to change
Ability to prioritise between competing demands.
Experience in office administration, facilities coordination, or similar operational role.
Basic understanding of EHSSS in an office environment (desirable).
Key Behaviours
Ownership – Take responsibility for the office environment and see tasks through to completion.
Proactivite – Anticipate issues and take action before they arise.
Attention to Detail – Maintain high standards and accuracy.
Service Focus – Create a positive and supportive experience for staff and visitors.
Collaboration – Build effective working relationships across teams and with external providers.
Why This Role Matters
This role is critical to maintaining a safe, compliant, and efficient workplace. The Office Administrator ensures the smooth running of the Harwell office, providing a positive experience for employees and visitors alike.
By maintaining strong control of office operations, facilities coordination, and EHSSS compliance, the role enables the wider team to perform at their best in a professional and supportive environment.
Our Culture
Our values are built on a strong foundation of safety, integrity, and respect for every individual. People are at the heart of our mission, and we believe in supporting one another through a culture of care and collaboration.
We strive to create a workplace where everyone feels they belong and can thrive. Supporting mental wellbeing and fostering a sense of connection are essential to how we work.
When we embrace different perspectives and work together, we become more innovative, more agile, and more successful.
We partner with VERCIDA, for greater online accessibility please visit www.vercida.com to view and access our roles. As a Disability Confident employer, we will interview all disabled applicants who meet the minimum criteria for a vacancy. We welcome applications from candidates who are seeking flexible working and from those who may not meet all the listed requirements for a role.
If you require further support or reasonable adjustments with regards to the recruitment process (for example, you require the application form in a different format), please contact the team.
Compensation Details:
GBP
The compensation range or hourly rate listed for this position is provided as a good-faith estimate of what the company intends to offer for this role at the time this posting was issued. Actual compensation may vary based on factors such as job responsibilities, education, experience, skills, internal equity, market data, applicable collective bargaining agreements, and relevant laws.
Benefits Overview:
Our health and welfare benefits are designed to support you and your priorities. Offerings include:
Health, dental, and vision insurance
Paid time off and holidays
Retirement benefits (including 401(k) matching)
Educational reimbursement
Parental leave
Employee stock purchase plan
Tax-saving options
Disability and life insurance
Pet insurance
Note: Benefits may vary based on employment type, location, and applicable agreements. Positions governed by a Collective Bargaining Agreement (CBA), the McNamara-O'Hara Service Contract Act (SCA), or other employment contracts may include different provisions/benefits.
Original Posting:
04/29/2026 - Until FilledAmentum anticipates this job requisition will remain open for at least three days, with a closing date no earlier than three days after the original posting. This timeline may change based on business needs.
Amentum is proud to be an Equal Opportunity Employer. Our hiring practices provide equal opportunity for employment without regard to race, sex, sexual orientation, pregnancy (including pregnancy, childbirth, breastfeeding, or medical conditions related to pregnancy, childbirth, or breastfeeding), age, ancestry, United States military or veteran status, color, religion, creed, marital or domestic partner status, medical condition, genetic information, national origin, citizenship status, low-income status, or mental or physical disability so long as the essential functions of the job can be performed with or without reasonable accommodation, or any other protected category under federal, state, or local law. Learn more about your rights under Federal laws and supplemental language at Labor Laws Posters.