Job Description

🌟 Join Sigma.AI – Shaping the Future of Artificial Intelligence 🌍

🔹 What is Sigma?

Sigma is a leading global technology company specializing in data collection and annotation for Artificial Intelligence. With over 30 years of experience, offices in Spain, the United States, and the United Kingdom, and operations in more than 700 languages, we support multinational clients in developing cutting-edge AI solutions.

👍 Soft Skills We Value:

Are you a proactive professional who enjoys challenges, values collaboration, and approaches every task with empathy, integrity, and a passion for learning?

If so, we’d love to hear from you!

💼 About the Role:

We are looking for a proactive and detail-oriented HR & Payroll Administrator to support our Human Resources and Administrative functions in our London office.

This role is ideal for someone with a solid foundation in UK employment law, payroll processes, and HR administration, who is looking to grow within a dynamic and fast-paced environment.

You will play a key role in supporting day-to-day HR operations, ensuring compliance with UK regulations, and maintaining accurate employee records.

You will play a key role in ensuring smooth day-to-day operations by supporting payroll preparation, employee administration, and cross-departmental coordination.

✅ Key Responsibilities:

• Prepare and organize basic payroll data for submission to the external payroll provider

• Provide administrative support in managing employee holidays, absences, and time tracking

• Assist in the preparation of employment-related documentation (contracts, termination letters, certificates, etc.)

• Support the Health & Safety (Occupational Risk Prevention) and Finance departments with administrative tasks

• Maintain accurate and up-to-date employee records and documentation

• Assist with general administrative duties as required

🔹 Requirements:

• 1–3 years of experience in HR administration and/or payroll

• Strong organizational skills and attention to detail

• Good communication skills, both written and verbal

• Ability to handle sensitive information with confidentiality

• Proficiency in Microsoft Office (Excel, Word, Outlook)

• Ability to multitask and prioritize effectively in a dynamic environment

• Fluency in English

• Ability to work on-site in London

⭐ Nice to Have:

• CIPD Level 3 (completed or in progress)

• Experience with HR systems (e.g. Workday, BambooHR, Sage, etc.)

• Experience in fast-paced or high-growth environments

• Spanish language skills

🚫 Important Notes:

Sigma.AI does not hire through third parties. No agents’ intermediaries or third parties are authorized to represent benefit from or participate in any way in the relationship. To this effect the Candidate agrees to provide any documentation or information reasonably requested by the Company to verify their identity and credentials. Should the Candidate fail to provide enough evidence of their identity to Sigma´s satisfaction, Sigma shall be entitled to withhold or terminate any offer with the Candidate.

The company may employ or rely on artificial intelligence systems in its selection processes. Such processing is carried out in an ethical, transparent, and legally compliant manner. The purpose of the processing is to evaluate the tests submitted in the course of the selection process (for instance the transcribed content provided by the candidate). The legal basis for processing your data is the pre-contractual relationship between the parties and/or the provision of requested services.

💬 Need Help?

We’re here for any questions or concerns.

Join us and be part of something global, innovative, and impactful.

Sigma.AI – Data done right.