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Top 50 professional services firms in South Holland

Tamtam tracks 145 professional services firms headquartered in South Holland. This list ranks the 50 largest by number of employees on LinkedIn, led by Kiwa, MN and Bilfinger Engineering. Their median headcount is 656. Half of them were founded in 1992 or later. The most common headquarters are Rotterdam (25), The Hague (7) and Rijswijk (4).

πŸ‡³πŸ‡± South Holland50 companiesUpdated Nov 13, 2026

The companies listed here are professional services firms in South Holland, primarily large organizations. They span a range of sectors including IT, financial services, engineering, and insurance.

Notable companies include Kiwa, a global leader in Testing, Inspection, and Certification; MN, offering solutions for pension funds and institutional investors; Centric, a partner in digital transformation; and OMA, an international architecture practice. The data shows a concentration of headquarters in Rotterdam, indicating a significant hub for these professional services firms.

#CompanyIndustryHeadquarters EmployeesFounded
1
Kiwakiwa.com

A global leader in Testing, Inspection, and Certification, offering a wide range of services to create trust in products and processes worldwide

Professional Services πŸ‡³πŸ‡± Rijswijk 4,320 n/a
2
MNmn.nl

A Netherlands-based company offering solutions for pension funds and institutional investors, specializing in investment management, pension administration, and management support

Financial Services πŸ‡³πŸ‡± The Hague 3,291 n/a
3
Bilfinger Engineeringbilfinger.com

Multidisciplinary engineering consultancy offering future-proof and sustainable solutions for industrial projects across various markets with a focus on project management and procurement

Engineering Services πŸ‡³πŸ‡± Schiedam 2,973 1945
4
Centriccentric.eu

A leading partner in digital transformation, providing software solutions, IT assessments, cloud services, staffing, and business process outsourcing to a diverse range of clients

IT Services and IT Consulting πŸ‡³πŸ‡± Gouda 2,900 1992
5
ICT Groupict.eu

Leading European provider industrial technology solutions. Delivers consultancy, software development, project solutions, managed services across vital sectors: automotive, high tech, industry, infrastructure, logistics, public mobility and safety.

IT Services and IT Consulting πŸ‡³πŸ‡± Barendrecht 2,462 n/a
6
CED Europecedgroup.eu

A European tech-enabled insurance services platform with a focus on expert claims management, innovation, and customer satisfaction through technology and personalized solutions

Insurance πŸ‡³πŸ‡± Capelle aan den IJssel 1,941 n/a
7
OMAoma.com

International architecture practice with a research and design studio, led by eight partners, known for innovative buildings worldwide, with offices in multiple cities

Architecture and Planning πŸ‡³πŸ‡± Rotterdam 1,905 1975
8
Zorgwerkzorgwerk.nl

Specializing in staffing solutions for the healthcare sector, providing excellent service to match supply and demand, with a focus on values like happiness and connectedness

Staffing and Recruiting πŸ‡³πŸ‡± Rotterdam 1,806 1997
9
Robecorobeco.com

An international asset manager specializing in sustainable investing, offering active investment strategies for institutional and private investors across various asset classes

Financial Services πŸ‡³πŸ‡± Rotterdam 1,482 1929
10
Iviv.nl

Specialist engineers solving complex issues related to energy transition, climate change, and societal resilience through innovative design solutions for various projects

Engineering Services πŸ‡³πŸ‡± Papendrecht 1,439 1949
11
CGI Nederlandcgi.com

Established in 1976, a global leader in IT and business consultancy, offering insights and results-driven solutions across 21 industries worldwide

IT Services and IT Consulting πŸ‡³πŸ‡± Rotterdam 1,435 1976
12
Bilfinger BelgiΓ« & Nederlandbilfinger.com

Industrial benchmark for projects and maintenance of industrial assets, ensuring safety and availability for clients in Belgium and the Netherlands Services include insulation, scaffolding, and more

Commercial and Industrial Machinery Maintenance πŸ‡³πŸ‡± Rotterdam 1,354 1950
13
Moore DRVmoore-drv.nl

Accountants and advisors supporting entrepreneurs in the real economy with expert insights, solutions, and support for lasting improvements in business performance

Financial Services πŸ‡³πŸ‡± Rotterdam 1,335 1922
14
Customs Support Groupcustomssupport.com

Leading European provider of customs and trade solutions enhancing cross-border operations, compliance, cost optimization, and operational efficiency.

International Trade and Development πŸ‡³πŸ‡± Rotterdam 1,037 1999
15
Kiwa Nederlandkiwa.com

A global leader in testing, inspection, and certification services, ensuring trust in products, services, processes, systems, and employees for clients worldwide

Professional Services πŸ‡³πŸ‡± Rijswijk 984 n/a
16
Ecorysecorys.com

This company provides research, consulting, communications, and management services to develop, deliver, and evaluate public policy on an international scale

Research Services πŸ‡³πŸ‡± Rotterdam 954 1929
17
Aethon.nlaethon.nl

Connecting talented individuals to meaningful work in various social sectors through training programs, ensuring continuity and flexibility for organizations while supporting career growth for individuals

Staffing and Recruiting πŸ‡³πŸ‡± Rijswijk 924 2005
18
AKDakd.eu

Delivers high-quality legal services and handles tax matters across nearly all legal fields in the Benelux region, involved in high-profile cases.

Law Practice πŸ‡³πŸ‡± Amsterdam 919 1917
19
Deernsdeerns.com

Independent engineering firm specializing in technical consulting and engineering solutions for various sectors worldwide, delivering high-quality services tailored to client's unique needs since 1928

Engineering Services πŸ‡³πŸ‡± The Hague 800 1928
20
Grant Thornton Netherlandsgrantthornton.nl

A member of Grant Thornton International Ltd, offering audit, tax, and advisory services with a global network of professionals

Professional Services πŸ‡³πŸ‡± Alphen aan den Rijn 776 n/a
21
TOS Peopletospeople.com

A family-owned maritime services provider offering selection, secondment, payroll, and training for various industries worldwide, focusing on people and quality service

Staffing and Recruiting πŸ‡³πŸ‡± Rotterdam 763 1992
22
WTS Energywtsenergy.com

Supporting organizations in the Energy Transition by providing expertise, flexibility, and technology for sustainable power generation projects through trusted partnerships and consistent service quality

Staffing and Recruiting πŸ‡³πŸ‡± The Hague 733 2000
23
GGNggn.nl

GGN is the largest debt collection and bailiff company in the Netherlands, focusing on helping individuals with financial difficulties while ensuring businesses get paid

Financial Services πŸ‡³πŸ‡± Rotterdam 720 2002
24
MetrixLabtolunacorporate.com

Global market research and insights provider challenging industry norms with technology and expert-driven solutions for brand impact and sustainable growth worldwide

Market Research πŸ‡³πŸ‡± Rotterdam 662 1999
25
Daandaan.eu

A company that matches individuals with passion and ambition to suitable jobs in healthcare, education, and social security through personalized support and development opportunities

Staffing and Recruiting πŸ‡³πŸ‡± Rotterdam 656 2012

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26
Schoo & Co.schooco.nl

A global consulting firm offering specialized services to insurance, shipping, and off-shore industries with a focus on expertise, sustainability, and client-centric approach

Maritime Transportation πŸ‡³πŸ‡± Rotterdam 629 1940
27
KH Engineeringkhe.eu

Multidisciplinary engineering firm offering full-service support for projects worldwide Specializes in innovative technological solutions with a focus on safety and sustainability

Industrial Machinery Manufacturing πŸ‡³πŸ‡± Schiedam 570 1949
28
VPSvpsveritas.com

A global leader in maritime decarbonisation advisory services, providing innovative testing and inspection solutions to optimize performance while reducing environmental impact

Professional Services πŸ‡³πŸ‡± Rotterdam 561 n/a
29
DevOndevon.nl

Accelerating enterprise success in the digital world through DevOps consultancy, transformation, training, and high performance teams specializing in software delivery and IT professionals

IT Services and IT Consulting πŸ‡³πŸ‡± Delft 545 2016
30
ICTUictu.nl

ICTU helps governments improve their services through innovative, high-quality ICT solutions, supporting collaboration between government levels and achieving concrete results for citizens and businesses

IT Services and IT Consulting πŸ‡³πŸ‡± The Hague 544 2001
31
DC

Multidisciplinary design agency specializing in developing visual identities for print and web, serving diverse clients in art, culture, brands, education, and government sectors

Design Services πŸ‡³πŸ‡± Rotterdam 532 1999
32
SKIMskimgroup.com

Global insights agency specializing in understanding decision-making for consumers, healthcare, and B2B professionals Offers practical marketing solutions through rigorous research techniques

Business Consulting and Services πŸ‡³πŸ‡± Rotterdam 513 1979
33
Ruarua.nu

RUA is a consultancy specializing in environmental management and participation, providing support in communication, stakeholder engagement, and community relations

Public Relations and Communications Services πŸ‡³πŸ‡± Rotterdam 500 2021
34
BPO bvbpo.nl

Specializing in product development, BPO offers end-to-end design solutions including analysis, prototypes, materials, sustainability, and testing for manufacturing efficiency

Engineering Services πŸ‡³πŸ‡± Delft 490 1987
35
216216.nl

This financial service provider uses knowledge, innovation, and technology to help entrepreneurs with automated, data-driven systems and comprehensive services

Financial Services πŸ‡³πŸ‡± The Hague 485 2015
36
valantic NLvalantic.com

Develops digital solutions, consulting services, and software, focusing on e-business, digital commerce, and marketing to integrate digital channels for client growth.

Business Consulting and Services πŸ‡³πŸ‡± Rotterdam 478 1992
37
iPS Powerful People (B Corpβ„’)ipspowerfulpeople.com

An international personnel provider in Maritime, Energy, Tunnelling & Civil industries offering transparent, flexible, and professional personnel solutions with global service

Staffing and Recruiting πŸ‡³πŸ‡± Capelle aan den IJssel 466 1988
38
Carrière Uitzendbureaucarriere.com

Committed to improving organizational performance, Carrière focuses on HR processes and values customer satisfaction, knowledge sharing, and top-notch service provision

Staffing and Recruiting πŸ‡³πŸ‡± Rotterdam 453 2010
39
Cardanocardano.nl

An investment management and advisory business focusing on risk and sustainability, supporting pension schemes to secure resilient financial outcomes for savers and society

Financial Services πŸ‡³πŸ‡± Rotterdam 448 2000
40
IDDSidds.nl

IDDS is a nationwide engineering and consulting firm, offering expertise in various areas such as environment, archaeology, water, and civil engineering

Real Estate πŸ‡³πŸ‡± Noordwijk 435 1988
41
Visser & Visservisser-visser.nl

A team of specialists at this company assists with international business ventures in the Netherlands, providing expertise in tax, employment law, and finance Through PrimeGlobal, they offer global support

Financial Services πŸ‡³πŸ‡± Rotterdam 434 1989
42
Pels Rijckenpelsrijcken.nl

Specializing in legal services, our team at Pels Rijcken provides tailored solutions for leading clients, particularly in the public sector Visit our website for more information

Law Practice πŸ‡³πŸ‡± The Hague 412 1969
43
TWDtwd.nl

Providing custom-designed solutions for offshore and heavy civil installation projects, including innovations, seafastening structures, lifting tools, and more Contact us for practical solutions 24/7

Civil Engineering πŸ‡³πŸ‡± Rotterdam 406 n/a
44
Recruitment Companyrecruitmentcompany.nl

Specializing in management search for industries such as technical, production, food, and logistics, recruiting talented managers with 5+ years experience and bachelor/master degrees

Staffing and Recruiting πŸ‡³πŸ‡± Rotterdam 389 1999
45
Public Supportpublicsupport.nl

Public Support is a team of supportive professionals dedicated to helping others excel, especially in the public sector, creating space for growth and trust

Staffing and Recruiting πŸ‡³πŸ‡± Lisse 387 2009
46
Van Ameyde Groupvanameyde.com

Global professional services firm specializing in insurance, claims, and risk management, providing swift solutions and unrivaled systems to secure clients' success worldwide

Insurance πŸ‡³πŸ‡± Rijswijk 382 n/a
47
MVRDVmvrdv.com

A Rotterdam-based architectural firm specializing in innovative and sustainable solutions for urban and architectural projects worldwide through collaborative and research-based design methods

Architecture and Planning πŸ‡³πŸ‡± Rotterdam 370 1993
48
Lubaluba.nl

Leading staffing agency for SMEs, specializing in quick matches between job vacancies and local talent through personalized communication and 50 nationwide branches

Human Resources Services πŸ‡³πŸ‡± Leiden 355 1968
49
Rebelrebelgroup.com

Development and advisory of public-private partnerships, innovative financing, project delivery, investment management, and strategic consulting across sustainability and social sectors.

Strategic Management Services πŸ‡³πŸ‡± Rotterdam 346 2002
50
Deerns Nederlanddeerns.com

An independent engineering firm providing consulting and engineering solutions globally, specializing in Airports, Healthcare, Data Centers, Laboratories, Cleanrooms, and Commercial Real Estate

Design Services πŸ‡³πŸ‡± The Hague 343 1928

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How this list is built

Every company on this list has a Tamtam company profile. The industry is the one the company gives on LinkedIn; categories such as SaaS or fintech are classified by Tamtam's AI from the company's website and LinkedIn page; and the headquarters city must match the company's own address. Companies are ranked by the number of employees on LinkedIn, and the list is refreshed every night. Classifications can be wrong, so treat the list as a starting point rather than an official ranking. Last updated Nov 13, 2026.

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