Types of Interpreting: How to Choose the Right Service

Interpreting is the spoken (or signed) transfer of meaning from one language to another, in real time, between people who do not share a language. It differs from translation, which deals with written text. NHS England's guidance defines interpreting as where "a conversation or discussion (for example, between a nurse and a patient) is re-produced in another language".

Buyers of interpreting face two separate choices: the mode, meaning when the interpreter speaks, and the format, meaning whether the interpreter is in the room, on the phone or on a video platform. This guide explains both, matches them to common settings, and links to our detailed guides on each topic. It is written for businesses, event organisers, HR teams, healthcare providers and anyone booking an interpreter for the first time.

What are the main types of interpreting?

There are five main interpreting modes. Each suits a different kind of communication.

Consecutive interpreting

Consecutive interpreting means the speaker pauses after a few sentences and the interpreter then renders what was said, often using notes. It works in both directions and needs no equipment, which makes it the standard mode for meetings, interviews, consultations and site visits. The trade-off is time: NHS England's guidance for commissioners says an interpreted consultation needs additional time, "typically double that of a regular appointment".

Simultaneous interpreting

Simultaneous interpreting means the interpreter speaks at the same time as the speaker, usually from a soundproof booth, while listeners use headsets. The event runs at normal speed, so this is the mode for conferences, AGMs and multilingual events. It is demanding work: the AIIC Italia professional standards state: "As a general rule, a team is composed of at least two interpreters per language and per booth."

Whispered interpreting (chuchotage)

Whispered interpreting is a form of simultaneous interpreting delivered quietly to one or two listeners sitting next to the interpreter, without a booth. It suits a board meeting or a small working session where only one or two people need language support, for short periods.

Liaison or escort interpreting

Liaison interpreting is informal, two-way consecutive interpreting for small groups, often while moving between places: factory tours, trade fair visits, business trips and partner dinners. The interpreter accompanies the group and interprets short exchanges as they happen.

Sight translation

Sight translation is the oral rendering of a written document, read aloud in another language. NHS England's guidance describes it as "reading information to the patient in the language required by them". It suits a short letter or form, but documents used repeatedly should be translated in writing.

Sign language interpreting

Sign language interpreting converts between a signed language, such as British Sign Language (BSL), and a spoken language. It is a separate profession with its own register: NHS England's guidance says BSL interpreters should meet the registration requirements of the NRCPD (the National Registers of Communication Professionals working with Deaf and Deafblind People), including "BSL level 6 or an honours degree in their second language". The same guidance notes that communication support such as sign language interpreting is likely to be considered a reasonable adjustment required under the Equality Act 2010.

How can interpreting be delivered: on site, by phone or by video?

Any interpreting mode can be delivered in person or remotely, and the format affects cost, flexibility and quality.

• On-site interpreting: the interpreter is in the room. Best for long, complex, sensitive or visual situations, such as negotiations, medical procedures or factory audits.
• Over-the-phone interpreting (OPI): the interpreter joins an audio call. Fast and economical for short, practical conversations.
• Video remote interpreting (VRI): the interpreter joins by video, usually working consecutively. Good for interviews and consultations where seeing faces matters.
• Remote simultaneous interpreting (RSI): interpreters work through a platform with separate language channels. ISO 24019:2022 covers platforms used "at communicative events where interpreters are not at the same venue as participants, speakers and signers".

Our earlier article on onsite or remote interpreting after the pandemic discusses how remote formats have grown.

Which type of interpreting suits which setting?

The setting usually determines the mode and format. The table below gives typical choices; your provider should confirm them for your specific event.

How do you choose the right interpreting service?

Choose an interpreting service by working from the people and the purpose to the mode and format, then to the provider. These steps cover most bookings:

1. Identify the languages and variants. Ask participants which language and dialect they prefer, for example European or Brazilian Portuguese.
2. Count the listeners and speakers. One or two listeners suits consecutive or whispered interpreting; a large audience needs simultaneous.
3. Decide how interactive the event is. Dialogue favours consecutive; presentations favour simultaneous.
4. Check the venue or platform. Confirm space for booths, the audio system, or the video platform's interpretation feature.
5. Assess sensitivity and risk. Medical, HR and legal settings need qualified, impartial interpreters and often an on-site presence.
6. Set the budget. Include minimum charges, travel, equipment and team size, not only the hourly rate.
7. Book early and brief well. Send preparation material and hold a short briefing before the event.

When you compare providers, ask the same questions of each:

• Is the interpreter a native speaker of the target language, and do they work in the variant or dialect your participants use?
• What experience does the interpreter have of your setting, such as healthcare, HR, engineering or finance?
• Which professional register or qualification does the interpreter hold, where one applies to your setting?
• What does the quote include: minimum time, travel, preparation, equipment and cancellation terms?
• How will confidential documents be shared and stored?

What standards and qualifications apply to interpreters in the UK?

Interpreting is not a regulated profession in the UK, so standards and registers are the main quality signals. The most relevant are:

• ISO 18841:2018, which according to ISO "specifies basic requirements for the provision of interpreting services" and also gives recommendations of good practice.
• ISO 23155:2022, which covers conference interpreting and, according to ISO, "also serves as reference for users of conference interpreting services".
• The National Register of Public Service Interpreters (NRPSI), which describes itself as "the UK's independent voluntary regulator of professional interpreters specialising in public service". The NRPSI website says there are "around 1,700 interpreters in 100 languages on the National Register".
• The Diploma in Public Service Interpreting (DPSI), whose health option NHS England's guidance expects of spoken-language interpreters in primary care; the guidance refers to it as the "Diploma in Public Sector Interpreting (Health)".

Professional codes also set ethical rules. The NRPSI Code of Professional Conduct requires interpreters to "interpret truly and faithfully what is uttered, without adding, omitting or changing anything". This is why a bilingual colleague is not a substitute for a professional; our article on why a professional interpreter is better than a bilingual person explains the difference. In courts and tribunals, interpreters are arranged through the justice system; GOV.UK explains how to get an interpreter at a court or tribunal, and our guide to court and tribunal interpreters in the UK covers this in more detail.

Interpreting guides: modes, formats and costs

These guides cover the practical decisions behind any interpreting booking.

• Consecutive vs simultaneous interpreting: compares the two main modes on timing, equipment, team size and cost, explains whispered interpreting and the ISO booth and equipment standards, and gives a step-by-step way to choose for your event.
• Remote interpreting by video and phone: explains telephone, video and remote simultaneous interpreting, how to set up interpretation channels in platforms such as Microsoft Teams, how to get good audio, and when on-site interpreting is still the better choice.
• How much an interpreter costs in the UK: sets out how interpreting is charged, published public-sector benchmarks such as the criminal legal aid rate of £32 per hour outside London and £29 in London, and the factors that change a quote.
• How to brief an interpreter: a checklist of what to send, when to send it and how to run a short briefing call, with tips for speakers and setting-specific advice.

Interpreting guides: settings and languages

These guides cover specific situations where interpreting is commonly needed.

• How to book an interpreter for a business meeting: the details a provider needs, which mode suits negotiations, visits and board meetings, how to protect confidentiality, and how to work with the interpreter on the day.
• Interpreters for HR investigations and disciplinary hearings: what Acas guidance says about interpreters, how the interpreter differs from the employee's companion, and how to run a fair interpreted meeting that stands up to scrutiny.
• Working with interpreters in healthcare settings: NHS England guidance on qualified interpreters, family members and children, appointment length and the interpreter's role, with steps for an interpreted consultation.
• European vs Brazilian Portuguese: a business guide to the differences between the two variants in writing and speech, what the 1990 Orthographic Agreement did and did not change, and how to choose the variant for translation and interpreting.

Why does interpreting matter for UK organisations?

Many people in the UK need language support for important conversations. The ONS Census 2021 language bulletin reports that 880,000 usual residents of England and Wales "could not speak English well" and 161,000 "could not speak English at all".

For employers, healthcare providers and service businesses, that means interpreting is part of running a fair and safe process, not only a matter for international trade. For businesses selling abroad, interpreters make negotiations, audits and partner visits possible in markets where English is not the working language.

Common mistakes when choosing an interpreting service

• Choosing the format before the mode. Decide how the conversation will work first, then whether it can be remote.
• Using bilingual staff or relatives in sensitive settings. They are not impartial and may not interpret accurately, especially in healthcare and HR.
• Booking one interpreter for long simultaneous sessions. Simultaneous interpreting needs a team that can take turns.
• Ignoring language variants. State the country or dialect, for example Brazilian Portuguese or Latin American Spanish.
• Underestimating time. Consecutive interpreting roughly doubles speaking time, so plan the agenda accordingly.
• Sending no preparation material. Even a short agenda and list of names improves accuracy.

How TranslationWorks can help

TranslationWorks is a UK-based language services agency that provides professional interpreting, translation, transcreation and transcription, working remotely with clients everywhere through native-speaking linguists in more than 150 languages. If you are not sure which type of interpreting you need, tell us the languages, setting, date, number of participants and location or platform, and we will recommend a suitable mode and format in a free quote within 24 hours. TranslationWorks has served more than 300 companies and is ISO 9001 and ISO 27001 registered and Cyber Essentials certified. See our interpreting services for the formats and settings we cover, or request a free interpreting quote.