Job Description

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 diversity and ethical excellence, this is the place where your ambition can thrive. We believe 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. If you're ready to join a team that values your unique perspective and is committed to your safety, well-being, and professional growth — we’d love to hear from you.

For our team in Krakow we are seeking a Tax Accountant/ Ksiegowy/ Ksiegowa ds. Podatkow.

The selected candidate will be employed by Critical Mission Solutions Sp. z o.o., part of Amentum.

The Tax Accountant will play a crucial role in supporting the Tax department in the day-to-day tax-related and accounting activities. The individual will work closely with the finance team and assist with the UK tax compliance, tax reporting and related matters. This is a great opportunity to be an instrumental contributor in furthering Amentum’s best-in-class tax function and for someone who enjoys working in a dynamic, diverse, and fast-paced environment.

Main responsibilities:

• Preparing corporate income tax return packages and associated calculations / workpapers in assigned jurisdictions.

• Assist with preparation and understanding of VAT and GST/HST Returns.

• Assist with quarterly and year-end tax provision workings, and preparing monthly tax journal entries, both locally and for Group Reporting.

• Preparing Tax Balance Sheet reconciliations.

• Assist with calculating and making corporate income tax payments.

• Assist with monthly tax cashflows and forecast.

• Work closely with Finance/Accounting teams to assist with tax related matters for statutory financial statement filings and audit

• Assisting with coordination and preparation of the UK’s Research and Expenditure Credit

• Maintain tax working papers, files and trackers.

• Assist with HMRC queries or other tax related queries.

• Assist with internal and external audit queries

Requirements:

• A Degree in Accounting, Finance or a related Business Degree

• Part Tax or Accounting qualified (ATT/ACCA/ACA) is a bonus but not essential

• Knowledge of Accounting GAAP – IFRS, US GAAP.

• Strong organizational, analytical, communication, and interpersonal skills

• Positive attitude and dependable team player with strong attention to detail

We Offer

International working environment and unique company culture fostering individual career growth and work-life balance

Personal development opportunities and training in industry-leading tools

Friendly and supportive team atmosphere

Participation in global projects and process improvements

Full-time employment contract with competitive salary

Benefits package including medical care, life insurance, My Benefit cafeteria with co-financing for sports activities, employee wellbeing support program

Flexible working hours (start between 7:30–10:00)

Short Fridays (Monday to Thursday we work 8,5h. Friday is a 6-hour workday)

Hybrid or stationary working model — based on your preference

Modern office in an attractive location

Our Commitment to Inclusion

We know that if we are inclusive, we’re more connected — and if we are diverse, we’re more creative. We welcome people for who they are, regardless of age, disability, gender identity or expression, marital status, mental health, race, faith or belief, sexual orientation, socioeconomic background, or family status.

Compensation Details:

Information regarding the salary for this position will be shared at later stages of the recruitment process, in a way that ensures transparent and well-informed negotiations.

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:

05/29/2026 - Until Filled

Amentum 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