An automatic speech recognition (ASR) system was developed as i part of AT&T's Intelligent Network in the United Kingdom for British Telecom. This work describes the algorithm development and presents the ASR recognition accuracy measured during an independent, country-wide performance trial of the system conducted in England in 1991. The hidden Markov model based system recognizes the words one, two, three, four, yes and no across eighteen English dialects in the UK. The country-wide isolated word performance of the system is 98.3%. Its performance on vocabulary words embedded in extraneous speech and noise is 94.4%.