Why People Search for ISO 27001 Certified Companies in the UK
If you have landed on this page, you are probably trying to do one of a few things. You might be a procurement manager checking whether a supplier holds a valid ISO 27001 certificate. You might be a business owner wondering who else in your industry is certified. Or you might be curious about how widespread ISO 27001 adoption actually is across the UK.
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All of those are legitimate reasons. But here is the honest answer upfront: there is no single public directory that lists every ISO 27001 certified company in the UK. There are, however, official databases you can search, and there are well-known organisations that publicly disclose their certification. This article will walk you through both, and explain exactly how to find and verify ISO 27001 certification for any UK company.
What Is ISO 27001 and Why Does It Matter in the UK?
ISO 27001 is the international standard for information security management systems (ISMS). It sets out a framework for identifying information security risks and putting the right controls in place to manage them. Certification means an independent, accredited auditor has verified that your organisation's security practices meet the standard.
In the UK, ISO 27001 has become one of the most in-demand certifications across technology, finance, healthcare, legal services, and government supply chains. The UK government's Cyber Essentials scheme is useful for baseline security, but ISO 27001 goes significantly deeper. Many public sector contracts now require ISO 27001 as a minimum, and large enterprise clients in financial services routinely ask for it during supplier due diligence.
If you want to understand the fundamentals of the standard before diving into who holds it, our beginner's guide to ISO 27001 covers the key requirements in plain language.
Well-Known ISO 27001 Certified Companies in the UK
Rather than a static list that becomes outdated the moment it is published, what is more useful is understanding which sectors have high certification rates and naming some of the well-known organisations that have publicly confirmed their ISO 27001 status.
Technology and Cloud Providers
The UK technology sector has very high ISO 27001 adoption. Major cloud and SaaS providers operating in the UK that hold ISO 27001 certification include:
- Microsoft holds ISO 27001 certification across its cloud infrastructure, including Azure and Microsoft 365 services.
- Amazon Web Services (AWS) is certified for its global infrastructure, including UK data centre regions.
- Google Cloud maintains ISO 27001 certification for its cloud platform.
- IBM UK holds certification across a range of its managed services and cloud offerings.
- BT Group maintains ISO 27001 across several of its business divisions.
- Vodafone UK holds certification for its enterprise and managed services divisions.
These are large organisations with publicly available compliance documentation. For smaller technology companies, certification is increasingly common but less publicly advertised. You need to ask directly or check the UKAS database, which we will cover shortly.
Financial Services
UK financial services firms face strong regulatory pressure around data security from the Financial Conduct Authority (FCA) and the Prudential Regulation Authority (PRA). ISO 27001 is widely adopted in this sector:
- HSBC UK holds ISO 27001 certification for various divisions and data processing environments.
- Lloyds Banking Group maintains ISO 27001 as part of its broader information security framework.
- Barclays holds certification across key parts of its technology and data operations.
- Experian UK is certified given its core business involves handling vast amounts of personal financial data.
Fintech companies and payment processors operating in the UK also tend to hold ISO 27001, often alongside PCI DSS. If you want to understand how those two frameworks compare, our article on ISO 27001 vs PCI DSS breaks down the differences clearly.
Government and Public Sector Suppliers
Many companies that supply to UK central government and NHS trusts hold ISO 27001 as a contractual requirement. Notable certified organisations in this space include:
- Capita holds ISO 27001 for various divisions that manage government data.
- Fujitsu UK is certified across its IT services and public sector contracts.
- Sopra Steria maintains ISO 27001 certification for its UK government services.
- Computacenter holds certification for its managed IT services.
For any supplier to Crown Commercial Service frameworks or NHS Digital, ISO 27001 is often explicitly listed as a requirement in tender documentation.
Legal and Professional Services
Law firms and professional services firms in the UK that handle sensitive client data are increasingly pursuing ISO 27001. Several of the Magic Circle and Silver Circle firms hold certification, as do a growing number of mid-market firms. Big Four accounting firms including Deloitte, KPMG, EY, and PwC all maintain ISO 27001 certification across relevant business units.
Managed Service Providers
MSPs in the UK are under growing pressure from their clients to demonstrate ISO 27001 certification. If you are an MSP looking at this from a competitive angle, our article on ISO 27001 certification for managed service providers explains exactly why it matters and how to approach it.
How to Find ISO 27001 Certified Companies in the UK Officially
This is the most important section of this article. If you need to verify that a specific company is ISO 27001 certified, do not rely on a certificate image they email you or a badge on their website. Certificates can be faked, expired, or issued by non-accredited bodies. You need to check official databases.
The UKAS Certified Organisations Directory
UKAS, the United Kingdom Accreditation Service, is the national accreditation body for the UK. It accredits the certification bodies that issue ISO 27001 certificates. UKAS maintains a public directory of organisations that have been certified by UKAS-accredited certification bodies.
You can search the UKAS certified organisations directory by company name, standard, or sector. This is the most reliable free tool for verifying ISO 27001 certification in the UK. When you find a company in this database, you can see which certification body issued their certificate, the scope of their certification, and whether it is current.
Checking Directly with Certification Bodies
Many of the major certification bodies operating in the UK maintain their own public registers. If you know which certification body a company uses, you can often search their database directly. The main UKAS-accredited bodies issuing ISO 27001 in the UK include BSI, Bureau Veritas, DNV, SGS, TUV, Lloyds Register, and NQA, among others.
Each of these bodies has a certificate verification tool on their website. You can typically enter a certificate number or company name to confirm validity. Our article on how to verify your ISO certificate online walks through this process step by step.
Asking the Company Directly
If you are a procurement manager conducting due diligence, you are entitled to ask a supplier for their ISO 27001 certificate and to confirm the details independently. A legitimate certificate will show the issuing certification body, the certificate number, the scope statement, the issue date, and the expiry date. You then cross-reference those details in the UKAS directory or the certification body's own register.
Be cautious if a company refuses to share their certificate number or is vague about which body issued it. That is a red flag worth investigating further. Our guide on how to spot fake ISO certificates covers the warning signs in detail.
How Many Companies in the UK Hold ISO 27001?
The UK consistently ranks among the top countries in the world for ISO 27001 adoption. According to the ISO Survey of Certifications, the UK has tens of thousands of valid ISO 27001 certificates, making it one of the highest-certified countries globally alongside Japan, China, Germany, and India.
The growth in UK certifications has been driven by several factors: the rollout of GDPR and the UK GDPR post-Brexit, increasing cyber threats, government supply chain requirements, and the broader shift toward cloud services where clients demand evidence of security controls.
Small and medium-sized businesses now make up a significant proportion of newly certified organisations. It is no longer just large enterprises. A ten-person SaaS company or a boutique IT consultancy can and does hold ISO 27001 certification, particularly when their client base includes enterprise or public sector buyers.
What ISO 27001 Certification Actually Covers
One thing that often confuses procurement teams is the scope of a certificate. ISO 27001 certification is not blanket coverage of an entire organisation. It applies to a defined scope, which is stated on the certificate itself.
For example, a large technology company might be certified for its cloud hosting services but not for its HR systems. A law firm might be certified for its document management and client data handling processes but not for its marketing operations. When you are verifying a supplier's certification, always check that the scope of their certificate actually covers the services or processes you care about.
This is a point that catches a lot of people out. A supplier can legitimately say they are ISO 27001 certified while their certification scope excludes the exact service they are providing to you. Always read the scope statement carefully.
Why Some Certified Companies Do Not Appear in Public Searches
Not every certified company will appear in a simple Google search or even in the UKAS directory. There are a few reasons for this:
- Some companies are certified by accredited bodies that are not UKAS-accredited. For example, a UK company might use a certification body accredited by DAkkS in Germany or COFRAC in France. Those certificates are still internationally recognised but will not show in the UKAS database.
- Some companies hold certification under a parent company's certificate, so searching for the subsidiary name returns nothing.
- Some companies simply do not publicise their certification, even though it is valid.
If a supplier claims certification but does not appear in UKAS, ask for the certificate and verify it through the issuing certification body's own register. International accreditation bodies are all members of the International Accreditation Forum (IAF), so certificates issued by any IAF member accreditation body carry equivalent international recognition.
Sectors With the Highest ISO 27001 Adoption in the UK
Based on certification data and industry trends, the sectors with the highest concentration of ISO 27001 certified organisations in the UK are:
- Information technology and software: This is by far the largest sector. SaaS companies, IT service providers, software developers, and data analytics firms make up a huge proportion of UK certificates.
- Financial services: Banks, insurance companies, fintech firms, and payment processors.
- Healthcare and life sciences: NHS suppliers, medical device companies, and clinical data management firms.
- Legal services: Law firms handling sensitive client and case data.
- Telecommunications: Network operators and managed communications providers.
- Government and defence supply chains: Companies supplying to central government, HMRC, the Home Office, and defence agencies.
- Consulting and professional services: Management consultancies, audit firms, and advisory practices.
Getting ISO 27001 Certified in the UK: What It Takes
If reading this article has prompted you to consider certification for your own organisation, here is a realistic overview of what is involved.
The Certification Process
ISO 27001 certification involves implementing an information security management system that meets the standard's requirements, conducting an internal audit, completing a management review, and then going through a two-stage external audit with an accredited certification body. Stage 1 is a documentation review. Stage 2 is an on-site or remote assessment of your implemented system.
Our article on the ISO 27001 certification process step by step gives you a detailed breakdown of each phase.
How Long It Takes
For most small to medium-sized organisations, the implementation and certification process takes between three and twelve months. The timeline depends on your starting point, your internal resources, and how complex your information environment is. Our dedicated article on how long ISO 27001 certification takes covers this in detail.
Choosing the Right Certification Body
In the UK, you want a UKAS-accredited certification body. This ensures your certificate is recognised by government, enterprise clients, and international partners. If you are not sure how to evaluate your options, our guide on how to select the best ISO certification body includes a free checklist that applies equally well to UK businesses.
Using CertBetter to Find the Right ISO 27001 Partner
Whether you are a UK business looking to get ISO 27001 certified for the first time or you are switching certification bodies, finding the right partner is one of the most important decisions you will make. The wrong consultant or certification body can cost you months and thousands of pounds.
CertBetter is a global platform that connects businesses with verified ISO consultants and accredited certification bodies. You submit one form, and you receive up to three competing quotes from vetted providers. The service is completely free for businesses seeking certification help. It removes the guesswork from finding a reputable ISO 27001 partner and gives you real options to compare.
