What Does ISO 17100 Certification Mean for a UK Translation Agency?

Key Takeaways

• ISO 17100:2015 is the international quality standard for translation services. It defines the minimum requirements for the people, processes, and resources involved in producing a professional translation.
• The most significant practical requirement of ISO 17100 is mandatory independent revision: every translation must be reviewed by a second qualified linguist before delivery. Self-review by the original translator does not satisfy the standard.
• ISO 17100 sets qualification requirements for both translators and revisers. Translators must hold a recognised translation qualification or a degree in the relevant subject area plus at least two years of professional translation experience.
• Certification is issued by an accredited certification body following an external audit. An agency claiming ISO 17100 compliance without third-party certification is not the same as one that has been audited and certified.
• For buyers commissioning translation for legal, medical, regulatory, or certified purposes, working with an ISO 17100 certified agency provides documented assurance that the translation process meets an internationally recognised standard.

When a translation agency describes itself as ISO 17100 certified, it is making a specific and verifiable claim about how it operates. ISO 17100:2015 is not a general mark of quality or a self-assessment framework. It is an internationally recognised standard published by the International Organisation for Standardisation, specifying the requirements for the core processes, resources, and other aspects necessary for the delivery of quality translation services.

Understanding what the standard actually requires, and what certification means in practice, helps buyers evaluate agencies more accurately and ask better questions before commissioning work.

What ISO 17100:2015 covers

ISO 17100:2015 defines requirements across five main areas.

Translator qualifications. Under the standard, translators must meet minimum qualification requirements. These are: a recognised university degree in translation, or a recognised university degree in any other field combined with at least two years of documented professional translation experience, or at least five years of documented professional translation experience. Agencies certified under ISO 17100 must be able to evidence that their translators meet these criteria.

Reviser qualifications. Revisers, the second linguist who independently reviews the translation, must meet the same qualification requirements as translators. An unqualified reviewer does not satisfy the standard.

Mandatory revision. This is the most operationally significant requirement. ISO 17100 mandates that every translation undergoes revision by a second qualified linguist before delivery. The reviser works bilingually against the source document, checking for accuracy, consistency, terminology, register, and completeness. Self-review by the original translator, however thorough, does not meet this requirement.

Pre-production processes. The standard requires agencies to confirm project feasibility, agree specifications with the client, and confirm that the appropriate resources are available before accepting a project. This includes language pair coverage, subject-matter expertise, and realistic turnaround capacity.

Technical and administrative requirements. ISO 17100 covers file handling, data security, use of translation memory and CAT tools, and the management of client assets including glossaries and style guides.

What certification means

Certification under ISO 17100:2015 is issued by an accredited third-party certification body, such as BSI (British Standards Institution) in the UK, following an external audit of the agency's processes, documentation, and operations. The audit verifies that the agency's actual practices conform to the standard's requirements, not just that the agency claims to follow them.

Certification must be renewed periodically, typically every three years, with surveillance audits in between. An agency that was certified five years ago and has not renewed is not currently certified.

An agency that claims to "follow ISO 17100 principles" or "work to ISO 17100 standards" without holding current third-party certification is making a different and weaker claim. It means the agency has read the standard and believes its processes are broadly similar. It does not mean an external auditor has verified this.

When evaluating agencies, ask to see the current ISO 17100 certificate and confirm the issuing body.

What ISO 17100 does not cover

ISO 17100:2015 is a process standard, not an outcome guarantee. Certification confirms that an agency's workflow meets defined requirements. It does not guarantee that every individual translation will be error-free, any more than a manufacturer's ISO 9001 certification guarantees that no defective product will ever leave the production line.

The standard also does not currently cover machine translation post-editing (MTPE) workflows. A separate standard, ISO 18587, addresses MTPE specifically. Agencies offering MTPE services alongside ISO 17100 certified human translation are operating under two different quality frameworks for those two service types.

Why ISO 17100 matters for buyers

For most translation buyers, the standard's mandatory independent revision requirement is the most practically significant element. It means that an ISO 17100 certified agency cannot legally deliver a translation that has only been reviewed by the person who wrote it. A second qualified professional must check it first.

For documents being submitted to courts, government bodies, and regulatory authorities, the ISO 17100 framework also provides a documented process trail. If a translation is questioned, the agency can demonstrate that it was produced by a qualified translator, reviewed by a second qualified linguist, and managed under a certified quality system.

For procurement teams and legal or compliance functions that require suppliers to hold recognised quality certifications, ISO 17100 is the translation industry's equivalent of ISO 9001 in manufacturing or ISO 27001 in information security.

Global LTS and ISO 17100:2015

Global LTS holds current ISO 17100:2015 certification. Every translation we deliver, regardless of subject matter, language pair, or turnaround time, goes through the mandatory two-stage workflow the standard requires: qualified subject-specialist translation followed by independent revision by a second qualified linguist.

For more information about our translation services and quality processes, visit our translation services page or contact us to discuss your project requirements.