Translation, Check, Revision, Verification: The Four Required Stages of ISO 17100

Why ISO 17100 Specifies a Workflow, Not Just Outcomes

Most quality management standards tell you what to achieve and leave the how largely up to you. ISO 17100 takes a different approach. For the production phase of a translation project, it prescribes a specific sequence of activities that must be followed. This is not guidance. It is a requirement.

The four stages are translation, check, revision, and verification. Each has a defined purpose, defined inputs and outputs, and in most cases, defined competence requirements for the person performing it. Understanding what each stage actually involves, and how they connect, is essential for anyone working with translation service providers, auditing them, or building a quality system that conforms to the standard.

This article walks through each stage in detail, explains what the standard requires, and highlights the common gaps that auditors find when assessing conformity.

Stage One: Translation

Translation is the core production activity. The translator takes the source content and produces a target language version that is accurate, complete, and fit for its intended purpose. Under ISO 17100, this is not simply a matter of converting words from one language to another. The standard sets out specific tasks the translator must perform as part of the translation activity itself.

What the Translator Must Do

Clause 5.3.1 of ISO 17100 requires the translator to perform the following tasks during translation:

• Translate the source content into the target language
• Apply any agreed terminology, style guides, or reference materials
• Resolve any queries about the source content or translation requirements
• Prepare the translated content for the next stage
• Identify and flag any issues that cannot be resolved independently

The standard also requires the translator to perform a self-review of their own work before passing it on. This is sometimes called a self-check or self-revision, and it is distinct from the formal check and revision stages that follow. It is the translator taking responsibility for the quality of their own output before it moves through the workflow.

Competence at the Translation Stage

ISO 17100 sets clear competence requirements for translators. These are covered in detail in Translator Qualifications Under ISO 17100: The Three Pathways After the 2017 Amendment, but the short version is that translators must meet one of three recognised pathways combining education, translation-specific training, and professional experience. The standard does not allow a translation service provider to use unqualified translators and compensate with more checking. Competence at the source is a baseline requirement.

Stage Two: Check

After the translator completes their work, the translated content moves to the check stage. The check is a quality control activity performed by the translator themselves, not by a second person. This is an important distinction that often confuses people encountering the standard for the first time.

What the Check Involves

The check is a review of the translated content against the source. The translator reads through their translation to verify that it is complete and accurate. Clause 5.3.2 specifies what the check must cover:

• Completeness: confirming that no content has been omitted
• Consistency: verifying that terminology and style are applied consistently throughout
• Accuracy: checking that the translation faithfully represents the source
• Compliance with project-specific requirements: confirming that any client instructions, style guides, or glossaries have been followed
• Formatting: ensuring the target content matches the required format

The check also covers more technical matters such as numbers, dates, measurements, and any content that could cause serious problems if rendered incorrectly. A translation of a medical document where a dosage has been transposed, or a legal contract where a date is wrong, represents a failure at the check stage.

Why the Self-Check Matters

Some people ask why the check is a separate named stage if it is still performed by the translator. The reason is accountability. By defining the check as a distinct activity with specific requirements, the standard creates a documented step in the workflow. The translator is not just expected to do good work. They are expected to verify it against a defined set of criteria before releasing it. This creates a clear point of responsibility and a record that the check was performed.

When auditing a translation service provider, you should be looking for evidence that the check is actually happening as a deliberate activity, not just assumed to be part of the translation process. Records, checklists, or workflow system logs that show the check was completed are the kind of evidence that demonstrates conformity.

Stage Three: Revision

Revision is where ISO 17100 becomes genuinely distinctive compared to most quality management frameworks. The revision stage requires a second, qualified person to review the translation. Not the same translator. A different person with their own defined competence requirements.

This is the signature requirement of the standard. For a more detailed discussion of why this matters and what it means in practice, see Why Revision by a Second Person Is the Signature Requirement of ISO 17100. The short version is that revision is not optional, it cannot be waived, and it cannot be performed by the same person who translated the content.

What Revision Covers

The reviser performs a bilingual review of the translated content against the source. Clause 5.3.3 sets out what the revision must assess:

• Appropriateness of the translation for its intended purpose and target audience
• Correct rendering of the source content in the target language
• Consistency of terminology and style
• Compliance with any domain-specific conventions or client requirements
• Completeness and accuracy
• Register and tone, where these are specified in the project requirements

The reviser reads the translation in the context of the source text. They are not simply proofreading the target language in isolation. They are assessing whether the translation works as a translation, not just whether it reads well in the target language.

Competence of the Reviser

ISO 17100 requires the reviser to meet the same competence requirements as a translator. They must have the qualifications and experience to translate in the relevant language combination and subject matter. A reviser who is fluent in the target language but has no translation training or experience in the relevant domain does not meet the standard's requirements.

The competence requirements for revisers are covered alongside those for reviewers and project managers in Reviser, Reviewer and Project Manager Competence Requirements in ISO 17100. When auditing, you need to verify that competence records exist for the reviser assigned to each project, and that those records demonstrate the required qualifications and experience.

What Happens When the Reviser Identifies Issues

Revision is not a passive activity. When the reviser identifies problems, they must either correct them directly or flag them for the translator to address. The standard does not specify a particular process for handling reviser feedback, but it does require that revision changes are made and that the revised content is the version that proceeds through the workflow. A revision that identifies problems but does not result in corrections is not a conforming revision.

In practice, this means the translation service provider needs a clear process for how revision findings are communicated, how corrections are made, and how the revised version is confirmed as the final output of the revision stage. Auditors should ask to see this process and trace it through actual project records.

Stage Four: Verification

Verification is the final quality check before the translated content is delivered to the client. Unlike revision, verification does not require a bilingual review. It is a target language check focused on the deliverable as a whole, confirming that it is ready for delivery.

What Verification Covers

Clause 5.3.4 specifies that verification must confirm the following:

• The final deliverable matches the agreed format and specifications
• All project-specific requirements have been met
• Any corrections from the revision stage have been incorporated
• The content is complete and ready for delivery
• Any client-specific requirements relating to the final output have been addressed

Verification may also include checks that are specific to the delivery format. For a translated website, this might include checking that links work and that the layout renders correctly. For a printed document, it might include checking page numbering and table of contents accuracy. For a subtitled video, it might include checking timing and character limits.

Who Performs Verification

ISO 17100 does not require verification to be performed by a qualified translator or reviser. It can be performed by the project manager or another member of the production team. What matters is that it is performed as a deliberate, documented activity before delivery, and that the person performing it has the knowledge to assess whether the deliverable meets the agreed requirements.

This flexibility makes sense. Verification is not a linguistic quality check in the same way that revision is. It is a final conformity check against the agreed project requirements. The competence required is knowledge of those requirements and the ability to assess whether the output meets them.

Verification vs Review

ISO 17100 also provides for an optional review stage, which is a monolingual target language review by a subject matter expert. Review is not part of the mandatory workflow. It is an additional service that can be agreed between the translation service provider and the client. Verification, by contrast, is mandatory. Every project must go through verification before delivery.

The distinction between verification and the optional review stage is explored in more detail in Review and Proofreading Under ISO 17100: When Are They Actually Required?. For auditing purposes, the key point is that you should not accept review as a substitute for verification. They serve different purposes and have different requirements.

How the Four Stages Connect

The four stages form a sequential workflow. Translation must be completed before the check can occur. The check must be completed before revision begins. Revision must be completed before verification. The standard does not permit these stages to be reordered or combined in ways that would undermine their individual purposes.

In practice, translation service providers use workflow management systems to track progress through each stage. When auditing, you should be able to follow a project from initiation through to delivery and see clear evidence of each stage being completed in sequence. If the workflow system shows revision being completed before the check, or verification happening before revision is finalised, that is a nonconformity.

Documented Evidence

ISO 17100 requires the translation service provider to retain records of the production process. This includes evidence that each stage was completed, who performed it, and what the outcome was. The level of detail required will depend on the project, but at a minimum, auditors should expect to see:

• Assignment records showing who performed translation, check, revision, and verification for each project
• Competence records for the translator and reviser
• Records showing that revision findings were addressed
• Confirmation that verification was completed before delivery

Gaps in these records are among the most common findings in ISO 17100 audits. Either the records do not exist, or they exist but do not contain enough information to confirm that each stage was performed by a qualified person in the correct sequence.

Common Audit Findings Against the Production Workflow

Based on how the standard is structured and what it requires, the following are the nonconformities that come up most frequently when auditing against Clause 5.3:

• Revision performed by the same person as translation. This is a clear nonconformity. The standard is unambiguous that revision requires a second, independent person.
• No competence records for the reviser. The translation service provider can demonstrate the translator's qualifications but cannot show that the reviser meets the same requirements.
• Verification not documented. The provider can show that translation and revision occurred but has no record of the final verification check before delivery.
• Revision findings not tracked to resolution. The reviser identified issues but there is no record of how they were addressed or who made the corrections.
• Stages performed out of sequence. Workflow records show verification completed before revision was finalised, or revision beginning before the check was recorded as complete.
• Check treated as part of translation with no separate record. The provider argues that the check is embedded in the translation process, with no documented evidence that it was performed as a distinct activity.

What This Means for Quality Managers and Auditors

If you are responsible for managing or auditing a translation service provider against ISO 17100, the production workflow is the heart of your audit. The four stages are not aspirational. They are mandatory, and conformity requires evidence that each stage was performed, by a qualified person, in the correct sequence, for every project.

This has practical implications for how you sample projects during an audit. You should select a range of projects, including some that are complex or high-risk, and trace each one through the full workflow. Ask to see the assignment records, the competence evidence for the people involved, the revision records, and the verification confirmation. If any of these are missing or incomplete, you have a finding.

It also has implications for how translation service providers design their quality systems. The workflow requirements of ISO 17100 need to be built into project management processes, not treated as an add-on. Providers who try to retrofit documentation onto an existing workflow that does not actually include all four stages will struggle to demonstrate conformity under audit.

Building Auditor Competence Across ISO Standards

ISO 17100 is a specialist standard, but the auditing principles that apply to it are the same ones that apply across all ISO management system standards. Gathering evidence, tracing processes, verifying competence records, and assessing whether documented requirements are actually being followed in practice are skills that transfer across every standard you audit against.

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