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Guide · For business

AI translation: when it’s enough, when it isn’t and what damage it can do

Machine translation has become good enough that its errors are hard to find. This page shows which texts it suits and which it doesn’t, which types of error are typical and what happens when nobody notices them. With a decision table and a checklist.

  • 11-minute read
  • Updated

In short

  1. AI translation is enough when a text is for information, stays internal and an error has no consequences.
  2. It isn’t enough once a text is published, binding or relevant to safety.
  3. In between lies post-editing: a machine translation checked by a professional, standardised in ISO 18587.
  4. The real risk isn’t obvious errors but fluent sentences that say something different from the original. Nobody reports them.
  5. Settle four things before you first use it: an approved tool, a glossary, the language variant and the level of review.

Four levels, not two

The question is rarely “AI or human”. In between are two levels that suit most corporate texts best: machine translation with light or full post-editing by a professional. Which level fits depends not on the budget but on what an error would cost.

Level What happens Suitable for Not suitable for
AI translation only Machine translation without human review Internal information, gist translation, large volumes, short-lived content Anything that is published or could have consequences
AI plus light post-editing A professional corrects errors of meaning, figures and terminology Internal documentation, support content, knowledge bases Marketing, contracts, safety-relevant content
AI plus full post-editing (ISO 18587) Full check against the source text, including style and terminology Product information, technical documentation, training material, large volumes with quality requirements Texts meant to have an effect rather than just inform
Specialist translation (ISO 17100) Translation by one professional, revision by a second Contracts, operating instructions, approval documents, annual reports, campaigns Nothing. The question here is rather whether transcreation is also needed

One point that is often overlooked in practice: a document doesn’t have to be assigned to a single level as a whole. The safety chapter of a manual can be handled as a specialist translation while the appendices and parts lists go through post-editing.

Which text needs which level

Three questions are enough to decide. Will the text be published? Would an error have legal or safety consequences? Should the text persuade or only inform? A yes to either of the first two questions means specialist translation.

Decision tree: first, will the text be published? Second, would an error have legal or safety consequences? Third, should the text persuade or only inform? A yes to either of the first two questions leads to specialist translation; otherwise AI with post-editing or AI alone is enough. WHICH LEVEL DOES YOUR TEXT NEED QUESTION 1Will the text bepublished?Customers, authorities, public QUESTION 2Would an error haveconsequences?Law, safety, compliance QUESTION 3Should the textpersuade?Or only inform Yes to question 1 or 2Specialist translation to ISO 17100, second pair of eyes included Only to informAI with or without post-editing When in doubt, what counts is not the average quality but the worst single sentence. A text can be split: the safety chapter as specialist translation, the appendices in post-editing.
The route to the right level. When in doubt, the worst single sentence decides, not the average.
Type of text Recommended level Why
Internal notes, minutes, emails for information AI only Nobody makes a binding decision on this basis
Support articles, FAQs, knowledge bases AI plus light post-editing Errors cost understanding, but rarely money
Product data sheets, catalogues, training content AI plus full post-editing Large volumes, fixed terminology, visible to customers
Operating instructions, safety notices and warnings Specialist translation Part of conformity, and errors can put people at risk
Contracts, terms and conditions, privacy policies Specialist translation One misunderstood sentence shifts obligations and liability
Approval and regulatory documents Specialist translation Authorities and notified bodies read them too
Websites, campaigns, slogans Specialist translation or transcreation Impact doesn’t come from literal accuracy
Annual and sustainability reports Specialist translation Figures, technical terms and a critical readership
Job adverts and internal communication AI plus post-editing Tone determines the effect, and errors are visible

What needs adapting beyond the translation itself is explained in our guide Translation or localisation?

Typical types of error and how to spot them

Machine translation makes different errors from people. It rarely fails on grammar and often fails on meaning, consistency and context. The difference from the past is that these errors now read completely naturally.

Type of error What it looks like What helps
Inconsistent terminology The same component has one name on page 4 and another on page 40, because the model translates each sentence separately Provide a glossary and translation memory, then spot-check
Numbers, units and formats Swapped decimal separators, unconverted units, a date that is read differently in the target market Check figures and units separately, not while reading
Negations and restrictions “Must not be operated without the protective cover” turns into a recommendation Always have safety-relevant sentences checked by a person
Ambiguous words The German “Anlage” as an investment, a plant or an attachment, depending on what the model thinks is most likely Provide context and write an unambiguous source text
Omissions and additions Language models smooth texts and occasionally drop clauses or add ones that aren’t in the original Compare section by section with the source text, rather than just reading the translation
Invented passages Where the source text has a gap, a language model fills it with plausible-sounding text Have anomalies flagged and check them against the original
Form of address and register Informal instead of formal address, or a form of politeness that is inappropriate in the target market Decide on the language variant and form of address in advance, including for every new edition
Format and markup Lost tags, broken placeholders, tables that fall apart Work in the file format rather than copying text, then run a technical check
Cultural references Examples, idioms and images that don’t work or cause offence in the target market Plan for localisation, not just translation

The most important consequence: you can’t check a translation by reading it. You can only check it by comparing it with the source text. If you only look through an AI translation for good German or good English, you won’t find the errors that matter.

What can follow

The cost of a poor translation rarely arises where the money was saved. Here are seven ways it comes back.

Liability and product safety

A badly translated warning isn’t a language problem but a product problem. After an accident, the documentation becomes evidence, and the way it was translated becomes part of the question of whether due care was taken.

Conformity and market access

From 20 January 2027, the EU Machinery Regulation applies to machinery. Instructions and declarations in the official language of each country are part of conformity. If a language version is missing or flawed, what is at stake isn’t the translation but your ability to deliver.

Contracts that apply differently from what you intended

In multilingual contracts, one version often prevails in a dispute. If the other version differs, both sides are negotiating different obligations without realising it, until it matters.

Silent errors that nobody reports

The most dangerous case isn’t obvious nonsense but a fluent, plausible sentence that says something different from the original. Nobody complains about it, because it reads correctly. It lives on for years, in every new edition and in every translation memory that takes it over.

Visibility in the target market

Literally translated texts miss the terms people search for in the target market. The page exists but isn’t found. That only shows up in the figures months later.

Confidentiality and data protection

If you upload contracts, personnel data or unpublished product information to any tool that comes to hand, you lose control of it. Without a data processing agreement and without clarity about server location and training, that is a data protection problem, however good the translation is.

Reputation with your audience

A text that sounds machine-made tells readers something about how seriously their market is taken. The damage is hard to measure and hard to repair.

None of this argues against using AI. It argues against choosing the level out of habit rather than by risk.

Checklist before you start

Nine points to settle before the first larger project. After that, every further run is routine.

Tool · Checklist

Using AI translation responsibly

Download the decision guide as a PDF (German)

Where AI translation really excels

Used properly, machine translation pushes back the limits of what is feasible: content that used to stay monolingual for cost reasons becomes translatable. That is the real gain, not the price per word.

Strength What it means in practice
Large volumes Product catalogues, knowledge bases and archives that would otherwise never have been translated
Speed First drafts in minutes, so decisions don’t have to wait for translations
Gist translation Incoming documents in languages nobody in-house can read
Groundwork A machine draft as a basis that a professional checks in a targeted way, instead of starting from scratch
Consistent building blocks Recurring sentences from the translation memory that don’t need translating again

The difference between useful and risky lies not in the technology but in the decision beforehand: do you know which level this text needs?

FAQ

When is AI translation enough?

When the text is meant to inform rather than persuade, when an error has no legal or safety consequences and when nobody outside the company will see it. Typical examples are internal notes, minutes and large volumes that only need to be understood.

When isn’t it enough?

As soon as a text is binding, published or relevant to safety: operating instructions, warnings, contracts, approval documents, annual reports, campaigns. What counts here is not the average quality but the worst single sentence.

Isn’t AI translation very good these days?

It is good enough that its errors are harder to find. That is the real difference from the past: machine translation used to be recognisable as such, but today even the wrong version reads fluently. Checking shifts from a feel for the language to comparison with the original.

What is post-editing?

The revision of a machine translation by a professional, standardised in ISO 18587. Light post-editing removes errors of meaning, while full post-editing brings the text up to the level of a specialist translation.

Can I upload contracts and personnel data to an AI tool?

Only to tools your company has approved and for which a data processing agreement is in place. Also check whether your input is used for training. If in doubt, the text doesn’t belong in a public tool.

How do I find out which level my text needs?

Three questions are usually enough. Will the text be published? Would an error have legal or safety consequences? Should the text persuade or only inform? A single yes to either of the first two questions means specialist translation.

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Written by the tolingo editorial team

Last updated 16 October 2026