Key takeaways
- Judge a translation agency on who actually translates and revises your text, not on the number of languages it lists.
- Ask for samples of similar work; the ITI advises buyers to request texts a supplier has produced, not just client names.
- Compare quotes on identical scope: revision step, language variant, file handling and translation-memory discounts.
- Decide in advance which content may be machine-translated and which needs full human translation and revision.
- For personal data, UK GDPR requires a written processor contract and control over any sub-contracted linguists.
This buyer's guide is for anyone choosing a translation provider in the UK: a procurement lead running a tender, a marketing manager launching in new markets, a law firm with a disclosure deadline or a small business translating its first contract. It explains what to look for, which questions separate capable agencies from resellers, and how cost, AI, quality standards and data security fit into the decision.
Each section summarises a detailed guide in this series, with a link to the full article. For the classic planning errors, read our earlier piece on mistakes to avoid when hiring a language service provider.
What should you look for in a translation agency?
Look first at the people and process behind the translation, then at security, transparency and service. A translation agency is only as good as the linguists it assigns to your text and the checks it runs before delivery.
| Criterion | What good looks like | Warning sign |
|---|---|---|
| Translators | Native speakers of the target language with subject expertise | Bilingual staff used instead of trained translators |
| Quality process | Revision by a second qualified linguist, plus automated checks | “Proofread” with no detail on who compares against the source |
| Evidence | Relevant samples, certificates you can verify, clear references to process | Logos only, no samples |
| Data security | Processor contract, ISO/IEC 27001 or Cyber Essentials, clear AI policy | No answer on where files go |
| Pricing | Itemised quote with word count, analysis and scope | Single figure with no breakdown |
| Communication | Translators ask questions; a named contact manages your project | No queries at all on complex text |
The Institute of Translation and Interpreting (ITI) gives buyers a simple test in its guide Translation: Getting it Right:
“Ask potential translation suppliers for samples of their work — not just client names, but texts they’ve produced and sold.”
How do you choose a translation agency, step by step?
A structured selection takes a few days and prevents most problems later. Follow these steps in order.
- Define the scope. List languages and variants, content types, volumes, deadlines and how the translation will be used: published, submitted, internal or for understanding only.
- Classify the risk. Decide which content could cause legal, safety, financial or reputational harm if wrong, and which content could use machine assistance.
- Shortlist providers with relevant experience. Look for sector expertise in your field, such as legal, medical or technical translation.
- Send the same brief and sample to each. Ask for an itemised quote, a proposed schedule and a description of the quality steps.
- Check evidence. Verify certificates, read samples with a trusted native speaker and ask how translators are selected.
- Agree contract terms. Confidentiality, data processing, AI use, ownership of translation memories and how complaints are handled.
- Start with a pilot. Use a real but limited project, review the result against an error scale and give structured feedback.
How much does translation cost, and how long does it take?
Translation in the UK is mostly priced per source word, and schedules are driven by how many words a translator can produce in a day. Both are covered in detail in two guides.
Translation cost per word in the UK
The UK Language Services Pricing Study 2020 by Nimdzi Insights, published by the Association of Translation Companies, found average agency rates from English of £0.120 to £0.157 per word depending on language group, with marketing and legal content on average 10% higher. Our guide to translation cost per word in the UK explains every price driver and how to compare quotes on equal terms. It also shows why reducing the number of words that need full-price translation saves more than negotiating the rate.
Realistic translation turnaround times
One professional translator typically produces 2,000 to 3,000 finished words a day, and revision, layout and client queries add time on top. Our guide to how long translation takes shows how to plan a deadline backwards from the go-live date and when splitting work between translators makes sense.
Do you need an agency, a freelancer or machine translation?
The sourcing route depends on languages, volume and the risk of error, and many organisations use more than one. Three guides cover the options.
Translation agency vs freelancer vs machine translation
A freelancer suits one language pair with steady volume; an agency suits multiple languages, large or urgent projects and work that needs managed revision; raw machine translation suits only low-risk internal text. Our comparison of agencies, freelancers and machine translation includes a decision table and five questions to settle the choice, and explains who carries the project-management work in each model.
Machine translation post-editing (MTPE)
MTPE is a workflow in which a linguist corrects a machine draft, either lightly for understanding or fully for publication, and it has its own standard, ISO 18587. Our guide to what MTPE is explains costs, suitable content and why MTPE is outside the scope of ISO 17100.
DeepL and ChatGPT for business translation
AI tools are useful for gisting, but published studies show accuracy varies sharply by language, and free versions may use what you paste in to train their models. Our assessment of whether DeepL and ChatGPT are good enough for business translation includes a risk table by content type. Our older article Humans vs Machines discusses why nuance still needs people.
Which quality signals should you check in a translation agency?
Quality is best judged from the process an agency follows and the resources it builds with you, rather than from claims of accuracy. Four guides explain what to look for.
ISO 17100 vs ISO 9001
ISO 17100 is the translation-specific process standard, ISO 9001 a general quality management standard and ISO/IEC 27001 an information security standard; each answers a different buyer question. ISO's certification page reminds buyers that “ISO does not perform certification or issue certificates”, so certificates must be checked with the issuing body. Our guide to ISO 17100 vs ISO 9001 shows how to verify one.
Translation quality assurance
Professional QA layers a self-check, bilingual revision by a second linguist, automated checks, optional expert review and a final layout proofread, and measures quality by grading errors. Our guide to how translation quality assurance works explains what each step catches and what your reviewers should do.
Translation memory
A translation memory stores approved sentence pairs so repeated and similar text is reused, which lowers cost and keeps wording consistent. Our guide to what translation memory is explains match types, analysis reports and why you should receive your TM in TMX format. Asking about TM ownership at the selection stage avoids being tied to one supplier later.
Glossaries and style guides
A glossary fixes key terms; a style guide fixes tone, form of address and formatting for each market. Our guide to translation glossaries and style guides shows what to include and how to build them with your translators.
How do you prepare your files and protect your data?
The buyer controls two things that strongly affect the result: the quality of the files sent and the security terms agreed. Two guides cover them.
Preparing files for translation
Final, editable source files, reference material and space for text expansion reduce cost and errors. Our guide on how to prepare your files for translation includes a format table and a nine-step checklist.
Data security when outsourcing translation
When documents contain personal data, the agency is normally your processor. Article 28 of UK GDPR states that “The processor shall not engage another processor without prior specific or general written authorisation of the controller”, which applies directly to freelance linguists. Our guide to data security when outsourcing translation lists the contract terms and questions to ask.
What questions should you ask a translation agency?
These questions reveal more about a translation agency than its website. Ask every shortlisted provider the same set.
- Who will translate my content, and what are their native language and subject expertise?
- Who revises the translation, and do they compare it with the source?
- Can you show samples of similar work, in my sector and language pair?
- Will you use machine translation or AI tools on my content, and which ones?
- Will freelancers or partner agencies handle my files, and in which countries?
- How are files transferred, stored and deleted, and who owns the translation memory?
- How is the quote calculated, and how are repetitions and matches treated?
- How do you handle queries, feedback and complaints?
Good providers welcome these questions. The ITI guide also notes that “No one reads your texts more carefully than your translator”, so expect a capable agency to ask you questions too.
How do you evaluate a sample or pilot translation?
Evaluate a sample or pilot translation with a native-speaking reviewer, the source text and a simple error scale, not by general impression. A fair evaluation compares like with like and separates real errors from personal preferences.
- Use real content. Choose 500 to 1,500 words that represent your typical material, including terminology and any tricky passages.
- Give every provider the same brief. Include the audience, purpose, language variant and any glossary you already hold.
- Choose a qualified reviewer. Ideally a native speaker who knows the subject, such as a colleague in your target market, briefed to compare the translation with the source.
- Grade errors by severity. Count critical, major and minor errors separately, and list preferences on their own; the method is described in our guide to translation quality assurance.
- Look at the process as well as the text. Note whether the provider asked sensible questions, met the deadline and documented the steps it followed.
The ITI guide also recommends running samples “past a trusted, language-sensitive native speaker (perhaps a foreign subsidiary or partner) for an opinion.” A provider that delivers a good pilot but cannot explain how it would scale the same quality to larger volumes or more languages is a risk for a long-term programme.
Common mistakes when choosing a translation agency
The most common mistake is choosing on the lowest per-word rate without checking what is included. Other mistakes that lead to poor results:
- Accepting a logo as proof. Check certificates, scopes and expiry dates.
- Skipping the pilot. A short real project tells you more than any proposal.
- Briefing nobody. Without purpose, audience and variant, translators guess.
- Using several agencies for one product. Terminology and translation memories fragment.
- Leaving AI use undefined. Agree in writing whether machine tools may be used.
- Treating translation as the last step. Late source changes are the main cause of overruns.
How TranslationWorks can help
TranslationWorks is a UK-based translation agency that provides professional human translation by native-speaking linguists in 150+ languages, and has served 300+ companies. Its services include translation, transcreation, transcription, interpreting and custom language services, across legal, medical and pharma, IT and gaming, industrial, e-learning, electronics, publishing and e-commerce content. TranslationWorks is registered to ISO 9001 (quality management) and ISO 27001 (information security) and is Cyber Essentials certified. To compare us with other providers, send your files and brief, and you will receive a free quote within 24 hours. See our translation services, custom language services or request a free quote.