ISO 18587: full post-editing by a qualified linguist of machine translation

The ISO 18587 standard sets out the requirements for post-editing machine-translation output so that the final text can reach a quality level comparable to human translation.

Professional team coordinating machine translation with ISO 18587 human post-editing

LinguaVox provides machine translation with full post-editing by a qualified linguist in accordance with ISO 18587 for projects where machine translation can bring speed or efficiency, but where the output cannot be delivered without professional human intervention. Before accepting a project, we assess the type of text, the language combination, the intended use, the terminology, the format and the required quality level.

What the ISO 18587 standard covers

ISO 18587 describes the requirements that apply to full post-editing by a qualified linguist of machine-translation output. Its purpose is not to replace the professional translator with an automatic tool. It defines how machine-translation output must be reviewed and corrected so that the result is suitable for the client, the reader and the intended use.

The ISO 18587 quality standard covers, among other aspects:

This point is important. ISO 18587 does not turn any machine-translation output into a professional text. The standard applies when a language service provider has a controlled process, qualified post-editors and clear criteria for reviewing the machine-translation output.

Machine translation, post-editing and full post-editing

A machine translation system is software that automatically translates a text from one language into another using artificial intelligence, without human intervention during the initial generation of the text. Current neural machine translation systems, such as DeepL, Google Translate and other specialised engines, produce more natural results than older rule-based systems. We discuss these solutions in more detail on the page about machine translation tools.

Even so, machine translation is not infallible. It can omit information, add nuances that are not in the source, misinterpret an ambiguous sentence, use the wrong terminology or produce a style that is not suitable for the sector. In technical, legal, medical, financial, commercial or publishable texts, these problems are not always obvious to someone who does not master both languages.

Post-editing is the process of modifying and correcting the machine-translation output. It can be light or full. Light post-editing is limited to correcting the most serious errors so that the text is understandable. Full post-editing, which is the focus of ISO 18587, aims to produce a result comparable to professional human translation.

For that reason, an ISO 18587 project is not just a matter of running a document through a machine translation engine and reading it quickly. The post-editor must work with the source text, the machine-translation output, the client’s instructions, the applicable terminology and the intended use of the final document.

More information is available on our human post-editing service and on what full post-editing involves.

When machine translation with human post-editing is effective

Machine translation with human post-editing can be effective when there is a high volume, a tight deadline, repetitive content, an extensive translation memory or an approved terminology glossary. It can also be a reasonable option when the client needs to balance cost, turnaround time and quality, provided that the source text and the language combination are suitable.

Not every document is suitable for this workflow. A company certified to ISO 18587 must assess the feasibility of combining machine translation and post-editing before the project starts. It should not be applied to every text by default, nor sold as a universal solution.

It usually works better with well-written texts, clear sentences, consistent terminology, repetitive structures and little ambiguity. It can be effective for technical documentation, manuals, product sheets, internal content, knowledge bases, software documentation, extensive web content or informative materials with enough repetition.

By contrast, it may not be recommended for highly creative texts, documents with a strong legal component, high-impact advertising materials, source texts with many errors, content with unstable terminology or texts where a literal translation could alter the meaning.

Before quoting an ISO 18587 post-editing project, LinguaVox analyses the available material and assesses whether machine translation can provide a real advantage. If the document is not suitable, we recommend human translation or a mixed workflow.

The post-editing process under ISO 18587

The post-editing process consists of modifying and correcting machine-translation output. The scope of ISO 18587 is limited to full post-editing by a qualified linguist, where the aim is to achieve quality similar to human translation.

In this type of project, the workflow does not begin with the review of the translated text. First, the provider must assess whether machine translation is feasible for that specific assignment. Then the project is prepared, the appropriate resources are selected, the post-editing is carried out and a final verification is performed before delivery.

Pre-production: feasibility, pre-editing and quotation

During pre-production, the material is analysed to decide whether machine translation and post-editing should be used for the document received. It is also assessed whether the source text should be prepared through pre-editing before it is processed by the machine translation system.

A document suitable for machine translation with post-editing usually meets several requirements: it is well written, uses simple sentences, avoids ambiguous structures, keeps terminology consistent, contains repetitive segments and does not overuse unnecessary synonyms.

When the source text does not meet these conditions, pre-editing can improve the machine-translation output and reduce the post-editor’s later effort. This stage is particularly useful when the document will be translated into several languages.

Once feasibility has been confirmed, the quotation is prepared. When the client accepts it and the agreement is formalised, the order is registered in the quality system and moves into the production stage.

Production: full post-editing by a professional post-editor

Human post-editing of machine-translation output is usually carried out in an environment that includes computer-assisted translation tools, machine translation engines, translation memories, terminology glossaries, client instructions and quality checks.

The post-editor is a translation professional with experience correcting machine-translation output. Their task is to read the machine translation and modify it so that the final text reaches a quality level comparable to human translation. To do this, they may correct errors, reformulate sentences, rewrite segments or provide a new translation when the automatic output is not usable.

In full post-editing, the provider must ensure that approved client glossaries, domain terminology, spelling and syntax conventions in the target language, the style guide, applicable standards, formatting rules and agreed instructions are followed.

Post-production: final verification, delivery and feedback

The result of full post-editing must be checked before final delivery. A company certified to ISO 18587 must apply quality controls and verify the document in accordance with what has been agreed with the client.

Post-editors must also be able to report recurring issues in the machine-translation output. This feedback helps improve the process, adjust instructions, detect terminology problems and assess whether the engine used is appropriate for similar future work.

Requirements for full post-editing

Full post-editing aims to make the result indistinguishable from professional human translation. To achieve this, the post-editor does not merely correct typos or poorly built sentences. They must check that the final text conveys the meaning of the source, uses the right terminology and is appropriate for the target audience.

The aspects to be controlled include the absence of omissions or additions, correction of inappropriate content, reformulation of ambiguous sentences, grammatical, syntactic and semantic accuracy, terminology consistency, spelling, punctuation, style and formatting.

This requirement is what separates full post-editing from a superficial review. In an ISO 18587 project, the final result must be publishable and usable according to the agreed specifications.

See the requirements for full post-editing.

Workflow from source text to machine translation, human post-editing and validated delivery

Competences and qualifications of post-editors

ISO 18587 attaches particular importance to the competences, qualifications and professional behaviour of post-editors. A post-editor is not simply a bilingual person correcting an automatic text. They must have translation competence, linguistic and textual competence in the source and target languages, research competence, cultural competence, technical competence and subject-matter competence.

The standard also sets out criteria to document their qualifications. These may include higher education in translation, linguistics or language studies, higher education in another field combined with professional experience, or several years of full-time experience as a translator or post-editor.

In addition, post-editors must be familiar with machine translation technology and the typical errors produced by these systems. They must be able to estimate the time and effort required, follow the instructions provided and make the necessary corrections so that the result is comparable to a human translation.

You can also consult the page about an ISO 18587 certified company and the explanation of what a professional post-editor does.

ISO 18587, ISO 17100 and ISO 5060

ISO 18587 is not the only quality standard relevant to translation services. ISO 17100 applies to professional translation services and defines requirements linked to processes, resources and revision. ISO 5060 is related to the evaluation of translation output, including human translation, post-edited machine translation and unedited machine translation.

They do not cover the same process. ISO 17100 is the natural reference for human translation. ISO 18587 is the reference when the starting point is machine-translation output and the client needs full post-editing by a qualified linguist. ISO 5060 helps explain how translation output can be evaluated.

See the comparison between ISO 18587, ISO 17100 and ISO 5060.

LinguaVox, ISO 18587 certified language service provider

LinguaVox is certified to ISO 18587 and can manage machine translation post-editing projects in many language combinations. We do not apply this workflow automatically. First, we assess whether the text is suitable and whether the expected benefit is real.

If the project fits, we prepare the workflow, select qualified post-editors, apply the client’s terminology and instructions, carry out full post-editing and check the final document. If it does not fit, we recommend human translation or a mixed process.

This approach is effective for companies that want to use language technology without giving up professional control. In practice, the value is not in the machine translation engine alone. The value lies in deciding when it should be used, how it should be reviewed and when it should be avoided.

Frequently asked questions about ISO 18587

What is ISO 18587?

ISO 18587 is a standard for full post-editing by a qualified linguist of machine-translation output. It defines requirements for the post-editing process, the tasks of the post-editor and the competences and qualifications of the professionals involved.

Does ISO 18587 certify machine translation engines?

No. ISO 18587 does not certify engines such as DeepL, Google Translate or other tools. It applies to the human post-editing process carried out after machine-translation output has been produced.

Is post-editing the same as revision?

No. Revision usually checks a translation produced by a human translator. Post-editing works on machine-translation output, which can contain different kinds of errors and requires specific professional judgement.

When is machine translation with post-editing recommended?

It is usually recommended for well-written, repetitive texts with controlled terminology, sufficient volume and a language combination in which machine translation can produce a usable output.

Can any document be processed under ISO 18587?

No. A feasibility assessment is needed. Creative texts, high-risk legal documents, sworn translations, sensitive medical reports or materials where nuance is critical may require human translation instead.

Is ISO 18587 post-editing always cheaper?

Not always. It can be more efficient in suitable projects, but if the machine-translation output is poor, the post-editing effort may be similar to or greater than human translation.

Request a quote for ISO 18587 post-editing

Send us your document, the required languages, the intended use, the desired deadline and any available terminology resources. We will assess whether machine translation with full post-editing by a qualified linguist is appropriate or whether another workflow would be safer.