Here’s our practical guide for UK companies looking to choose an ISO certification provider, with an expanded list of 20 prominent bodies that either operate in the UK or are widely used by UK businesses.
Most are UKAS-accredited, meaning they’ve been assessed by the United Kingdom Accreditation Service against internationally recognised standards like ISO/IEC 17021-1 for management system certification — a key factor in credibility and acceptance of the certificate you receive.
What to consider when choosing a provider
Before picking a certification body, keep these in mind:
- UKAS accreditation: Certificates from UKAS-accredited bodies are widely accepted by clients and are often required for public sector tenders and supply chain qualification. Use the UKAS directory or CertCheck to verify accreditation.
- Standards covered: Ensure the provider covers the specific ISO standard(s) you need (for example, ISO 9001, ISO 27001, ISO 14001).
- Industry experience: Experience in your sector can lead to better insights during audits.
- Audit approach and support: Clarify what support they provide during the audit and how they manage surveillance visits.
- Reputation and references: Look for client testimonials or ask for references from similar organisations.
Leading ISO certification providers the UK
Below are 20 recognised certification bodies that serve organisations seeking ISO certification in the UK. Many are UKAS-accredited; some operate internationally with UK presence:
- BSI Assurance UK Limited (British Standards Institution) – One of the most established certification bodies in the UK and globally active.
- Alcumus ISOQAR Limited – UKAS-accredited registrar covering quality, environment and information security standards.
- LRQA Limited (Lloyd’s Register Quality Assurance) – Strong global reputation and expertise across many ISO standards.
- NQA Global Certification Body – Internationally known provider with a significant UK client base.
- SGS United Kingdom Limited – Part of a global certification network with broad sector coverage.
- QEC Certification – UKAS-accredited with decades of experience in management system certification.
- Centre for Assessment – UKAS-accredited for multiple management system standards.
- British Assessment Bureau – Specialises in ISO 9001, 14001, 45001, 27001 and more.
- Interface NRM – UKAS (and ASI) accredited; also offers other scheme certifications.
- Auva Certification Ltd – Offers audits and certification with training options.
- Atlas Certification Limited – UK-based body with range of ISO standards supported.
- ForeFront Certification Limited – UKAS-accredited body covering quality, environment and health & safety.
- ACS Registrars – Frequently recommended by independent consultants (via industry guides).
- AJA Registrars – Another commonly used accredited registrar, especially for ISO 9001 and related standards.
- BM Trada Certification – UKAS-accredited, known for quality and construction-related standards.
- Certification Europe – Provides certified services and has presence with UK clients.
- Certification International – International accreditation with UK engagements.
- Intertek – Well-known global conformity assessment body working with management systems.
- Registrar of Standards (United Registrar of Systems) – Experienced ISO certification registrar.
- ISOQAR – UKAS-accredited provider with particular emphasis on ISO 9001 and related standards.
Verifying accreditation and choosing wisely
To make your choice with confidence:
- Check UKAS accreditation: Use the UKAS website or CertCheck to confirm that the provider is accredited for the specific standard.
- Compare audit programmes: Ask about audit frequency, timelines, and what documentation they require.
- Seek feedback: Speak to similar companies about their experience with a provider, especially in your sector.
Accredited certification not only improves internal systems but also signals credibility and quality to customers, partners and regulators alike — particularly important when competing for contracts or operating in regulated sectors.
Regional ISO certification providers
If you’d prefer to work with a local certifying body or consultant, see our individual guides:
FAQ about ISO certification providers
An ISO certification provider (also called a certification body or registrar) is an independent organisation that audits your management systems and, if they meet the required standard, issues an ISO certificate such as ISO 9001 or ISO 27001.
Yes, in most cases. A provider accredited by United Kingdom Accreditation Service has been independently assessed for competence and impartiality. UKAS-accredited certification is often required for public sector contracts and larger supply chains.
Certificates from non-UKAS bodies may still be valid, but they are sometimes rejected by councils, NHS organisations, construction frameworks, and corporate procurement teams. Always check tender requirements before choosing a non-accredited provider.
The ISO standard itself is the same worldwide, but the credibility of the certificate depends on the certification body. Certificates issued by UKAS-accredited providers carry significantly more weight in the UK market.
Most UK SMEs achieve certification within 8–16 weeks, depending on readiness, company size, and the ISO standard. Complex standards such as ISO 27001 often take longer than ISO 9001.
Typical costs range from £900 to £3,000+ per year for small businesses, depending on staff numbers, standard(s) chosen, and audit days required. UKAS-accredited providers are usually more expensive but more widely accepted.
Not always. Many businesses prepare internally using templates and guidance. Consultants can speed things up, but they are optional. Certification bodies themselves must remain independent and cannot help you write your systems.
Certification normally runs on a three-year cycle:
Year 1: Initial certification audit
Years 2–3: Annual surveillance audits
Year 4: Re-certification audit
Yes. Most UK providers can audit and certify multiple standards together, such as ISO 9001, ISO 14001 and ISO 45001, which can reduce audit time and cost.
No ISO standard is legally mandatory. However, many businesses require ISO certification to win contracts, meet supplier requirements, or operate in regulated sectors such as construction, IT, and healthcare.
Use the official UKAS CertCheck directory to confirm that the certification body is accredited for the specific ISO standard, not just in general.
Yes. ISO certificates issued by UKAS-accredited providers are recognised internationally through global accreditation agreements, making them suitable for overseas clients and partners.
Certification: Your business is audited and certified to an ISO standard.
Accreditation: The certification body itself is assessed and approved by UKAS.
Both matter, but accreditation is what gives your certificate authority.
Compare:
UKAS accreditation status
Experience in your industry
Audit approach and communication style
Long-term costs (surveillance and re-certification)