Review and Proofreading Under ISO 17100: When Are They Actually Required?

The Question Translation Providers Keep Getting Wrong

ISO 17100 is the international standard for translation services. It sets out requirements for translation workflows, personnel competence, and quality assurance processes. If you are seeking certification to ISO 17100, or if you are auditing a translation service provider against it, one of the most commonly misunderstood areas is the role of review and proofreading in the production workflow.

The confusion usually goes like this. A translation project manager says their workflow includes review and proofreading as standard. An auditor checks the documented procedure and finds that review is listed as optional, or that proofreading is only applied to certain project types. Is that a nonconformity? The answer depends on what the standard actually says, what the client agreed to, and how the organisation has documented its processes.

This article breaks down exactly when review and proofreading are required under ISO 17100, when they can legitimately be excluded, and what auditors should be looking for when they examine a translation workflow.

A Quick Recap of the ISO 17100 Production Workflow

ISO 17100 defines a mandatory production workflow in Clause 5. The core required steps are translation, check, revision, and a final verification step before delivery. These are not optional. Every project that falls within the scope of ISO 17100 certification must go through all four of these stages.

If you want a deeper look at how these four stages work in practice, the article on Translation, Check, Revision, Verification: The Four Required Stages of ISO 17100 covers each one in detail. The short version is that revision, which is the review of the translated text against the source by a second qualified translator, is mandatory. It is the signature requirement of the standard. Skipping revision is a major nonconformity.

But what about review and proofreading? These are different steps, and the standard treats them differently.

What ISO 17100 Says About Review

Review Is a Post Revision Step

Under ISO 17100, review is defined as an examination of the target language content for its suitability for the agreed purpose. Review is conducted by a subject matter expert, not necessarily a translator. The reviewer checks whether the translation reads naturally, whether the terminology is appropriate for the target audience, and whether the content achieves its intended purpose in the target language.

Importantly, review in ISO 17100 is not a required step in every project. The standard makes review conditional on the project agreement. If the client has requested review, or if the service agreement specifies that review will be carried out, then the translation service provider must perform it. If the agreement does not include review, the provider is not obligated to carry it out.

When Review Becomes Mandatory

Review becomes a mandatory step in the workflow when it has been agreed upon with the client during the pre production phase. This is covered in Clause 4, which deals with enquiries, quotations, and project agreements. If the signed agreement or project specification includes review as a deliverable, it must be performed, documented, and any feedback from the reviewer must be addressed appropriately.

From an audit perspective, this means you need to look at both the project agreement and the production records. If review is listed in the agreement, there should be evidence that it was carried out. If it is not in the agreement, the absence of review is not a nonconformity.

What Auditors Should Check

When auditing this requirement, look for the following:

• Does the organisation have a documented process for determining whether review is included in a project?
• Is the decision to include or exclude review captured in the project agreement or job specification?
• When review is agreed upon, are there records showing it was performed?
• Is the reviewer identified and does their competence meet the requirements set out in Clause 3?
• When the reviewer raises comments or changes, is there a documented process for handling those changes?

A common finding in translation company audits is that review is listed as a service offering but there is no consistent process for documenting when it was performed, who performed it, or how reviewer feedback was handled. That is where the nonconformity lies, not in the absence of review on every project, but in the absence of a controlled process when review has been agreed upon.

What ISO 17100 Says About Proofreading

Proofreading Is Also Conditional

Proofreading under ISO 17100 refers to the examination of the formatted target content against the formatted source content, or simply the examination of the formatted target content on its own. The focus is on the final formatted document, checking for layout errors, formatting inconsistencies, truncated text, and typographical issues that may have been introduced during the desktop publishing or formatting process.

Like review, proofreading is not a mandatory step for every project. It becomes required when it is specified in the project agreement. If the client is receiving a formatted document and has requested proofreading of the final output, the translation service provider must carry it out. If the deliverable is a plain text file and no proofreading has been agreed upon, it is not required.

Where Proofreading Fits in the Workflow

Proofreading sits at the end of the production workflow, after translation, check, revision, and any formatting or desktop publishing work. It is the final quality check before the translated content is delivered to the client. In projects involving complex layouts, such as marketing brochures, technical manuals, or legal documents with specific formatting requirements, proofreading is particularly important because the formatting process itself can introduce errors that were not present in the translated text.

From an audit perspective, the key question is whether the organisation has a clear process for identifying when proofreading is required, assigning it to a competent person, and documenting the outcome.

Auditor Questions for Proofreading

When examining proofreading in an ISO 17100 audit, consider asking:

• How does the project manager determine whether proofreading is required for a given project?
• Is that determination documented in the project file?
• Who performs proofreading and what are their competence requirements?
• What records are kept to show that proofreading was completed?
• If errors are found during proofreading, what is the process for correcting them and re checking?

One scenario that comes up regularly in audits is a translation company that performs proofreading as a matter of course on formatted documents but has never documented it as a step in their workflow. When the auditor asks for evidence of proofreading, the project manager says it happens but cannot produce any records. That is a documented information gap, and depending on the scope of the finding, it may be a minor nonconformity against Clause 7.5 of ISO 17100, which deals with documented information requirements.

The Practical Difference Between Review and Proofreading

It is worth being clear about this because the two terms are often used interchangeably in the translation industry, but ISO 17100 treats them as distinct activities with different purposes.

• Review is about suitability for purpose. It asks whether the translation achieves what it needs to achieve in the target language and for the target audience. It is performed by a subject matter expert, not necessarily a linguist.
• Proofreading is about formatted output quality. It asks whether the final formatted document is free from layout errors, truncation, and formatting inconsistencies introduced during production. It focuses on the physical presentation of the content.

A translation company might perform revision on every project (mandatory), offer review for technical or marketing content (conditional on agreement), and offer proofreading for formatted documents (conditional on agreement). That is a perfectly compliant structure, provided each step is documented and controlled appropriately.

Common Misunderstandings in ISO 17100 Audits

Treating Review as Synonymous with Revision

This is perhaps the most common confusion. Revision, which is the examination of the translation against the source by a second qualified translator, is mandatory. Review, which is the examination of the target content for suitability for purpose by a subject matter expert, is conditional. Conflating the two leads to either over documenting review as if it were mandatory, or under valuing revision by treating it as just one of several optional quality steps.

When you are auditing, make sure the organisation's documented procedures clearly distinguish between revision and review, and that the workflow records reflect which step was performed on each project.

Assuming Proofreading Replaces Revision

Some translation providers, particularly smaller operations, try to argue that proofreading serves the same purpose as revision. It does not. Revision is a linguistic quality check performed against the source text by a second qualified translator. Proofreading is a formatting quality check performed on the final document. They are not interchangeable. An organisation that performs proofreading but skips revision is not conforming to ISO 17100, regardless of how thorough the proofreading process is.

No Agreement Documentation for Optional Steps

Another common issue is that translation companies offer review and proofreading as services but do not consistently capture whether they have been agreed upon in the project documentation. If a client requests review verbally and the project manager performs it, but there is no record in the project file showing that review was agreed upon and carried out, the auditor cannot verify conformity. The organisation needs a process that captures service agreements consistently across all projects.

The article on ISO 17100 Clause 4 Pre Production: Enquiries, Quotations and Agreements covers how those pre production agreements should be structured and documented.

How to Audit Review and Proofreading Effectively

Start with the Documented Procedure

Before looking at individual project files, ask to see the organisation's documented production workflow. This should clearly identify all the steps in the workflow, indicate which steps are mandatory for every project, and show how conditional steps like review and proofreading are triggered and controlled.

If the procedure does not distinguish between mandatory and conditional steps, or if it simply lists all steps as standard without any mechanism for determining applicability, that is a gap worth exploring further.

Sample Project Files Across Different Project Types

Select a sample of completed project files that covers a range of project types, languages, and clients. For each project, check:

1. What services were agreed upon in the project specification or agreement?
2. Does the production record show that all agreed steps were completed?
3. If review or proofreading was agreed upon, is there evidence it was performed and by whom?
4. If review or proofreading was not agreed upon, is the absence of those steps consistent with the project documentation?

This approach lets you verify both that the organisation performs review and proofreading when required, and that it does not claim conformity with steps it has not actually performed.

Check Competence Records for Reviewers and Proofreaders

ISO 17100 sets out competence requirements for everyone involved in the production workflow. If review is performed, the reviewer must have the appropriate subject matter expertise. If proofreading is performed, the proofreader must have the relevant skills. Check that the organisation has competence records for the people performing these roles, not just for translators and revisers.

The article on Reviser, Reviewer and Project Manager Competence Requirements in ISO 17100 provides a detailed breakdown of what those competence records need to demonstrate.

Look at How Reviewer Feedback Is Handled

One area that often reveals process weaknesses is how the organisation handles feedback from reviewers. When a reviewer identifies issues with a translation, there should be a documented process for how those issues are communicated to the translator or reviser, how they are resolved, and how the resolution is recorded. If the organisation cannot show you this process, or if project files show reviewer comments with no evidence of follow up, that is a finding worth raising.

What Good Looks Like in Practice

A well run translation company operating under ISO 17100 will have a production workflow that clearly identifies revision as a mandatory step, and review and proofreading as conditional steps that are triggered by the project agreement. The project management system will capture the agreed scope of services for each project, and the production records will show which steps were performed, by whom, and when.

When review is performed, there will be records of the reviewer's comments and evidence that those comments were addressed. When proofreading is performed, there will be a record of the proofreader's check and any corrections made. When neither review nor proofreading is included in the project, the project file will show that these steps were not part of the agreed scope.

That is the level of control an auditor should be looking for. It is not about whether every project has review and proofreading. It is about whether the organisation has a controlled, documented process for determining when those steps apply and for executing them consistently when they do.

Implications for ISO 17100 Certification

If you are a translation service provider preparing for ISO 17100 certification, the key takeaway is this: you do not need to offer review and proofreading on every project, but you do need a clear, documented process for managing them when they are part of the agreed scope. Your workflow documentation should make it easy for an auditor to trace any project from the initial agreement through to delivery and verify that every agreed step was completed.

If you are an auditor examining a translation company's ISO 17100 compliance, resist the temptation to raise a nonconformity simply because review or proofreading was not performed on a particular project. Check the project agreement first. The real question is whether the organisation's process is controlled and whether the records support the claims being made.

Understanding how these conditional steps fit within the broader certification framework is important for anyone auditing translation service providers. If you want to sharpen your skills in auditing service organisations and understanding how ISO standards apply in non manufacturing contexts, the ISO 9001 Lead Auditor and Internal Auditor courses at Audit Workshop provide a strong foundation in process based auditing that translates directly to standards like ISO 17100. The practical focus on evidence gathering, workflow tracing, and documented information review is exactly the skill set you need when auditing a translation company against this standard.