For a person to call themself a "BSL/English Interpreter", you should expect their details to be recorded with the National Register of Communication Professionals with Deaf and DeafBlind People (NRCPD). This is the only national Register of BSL/English Interpreters for England, Wales and Northern Ireland. All BSL/English Interpreters on the Register commit to the NRCPD's Code of Conduct and Guidelines of Professional Practice. There are currently three levels of membership, the highest being 'Member of the Register of Sign Language Interpreters' (MRSLI).

Ideally, the person should also be registered with The Association of Sign Language Interpreters (ASLI) which is the professional association of BSL/English Interpreters for England and Wales. ASLI has different levels of membership, the highest of which is 'Full Member' (MASLI).

Both NRCPD and ASLI require their registered BSL Interpreter members to hold a current Enhanced CRB check (no more than three years old).

The British Deaf Association currently estimate that there are around 250,000 deaf people in the UK who use BSL as their first or preferred language (this includes both people born deaf as well as those who became deaf at some later point in their life from early childhood onwards). To meet this demand, there are currently around 320 MRSLI and around 150 Trainee/Junior Trainee interpreters throughout England, Wales and Northern Ireland.

For Greater London, based on a population of 7 million people, conservative estimates suggest that there are a minimum of 7000 born-deaf people who use BSL as their first or preferred language. This number increases when including those who became deaf at any later point in their lives and now use BSL as their first/preferred language. To meet this local demand, there are around 55 MRSLI and a further 20 Junior Trainee & Trainee interpreters registered with NRCPD in Greater London. That's just 75 people.

Given this shortage, there is a huge demand for BSL/English Interpreters so it is important to book as far in advance as possible either directly or via a specialist BSL/English interpreting agency. It may be possible to book at shorter notice due to a prior booking having been cancelled etc but this should not be relied upon.

Sadly, this means that there are some people who call themselves 'interpreter' but are not members of NRCPD or ASLI. Their level of skill in BSL and/or English as well as their interpreting ability is usually significantly below that of a suitably trained BSL/English Interpreter. Similarly, there are some agencies who provide individuals who may not have the necessary skill or training.

With this in mind, there was an Agency Steering Group whose member agencies committed to upholding high professional standards. Although the Steering Group no longer meet, you can find which agencies were members by looking at the 'Link' page.

Sometimes a BSL/English Interpreter is incorrectly called a "Signer". This term is more often used to describe people who are learning to become BSL/English interpreters. These people are likely to have less fluency with BSL than interpreters and have often not yet been taught the necessary processes involved in effective interpreting. Other terms to  "Signer" include Communication Support Worker or Communicator, both of which usually work in education with deaf pupils.