The phone number for the people who built the body of my car in 1927 is shown on their little plaque - "Telephone 8, Derby".
The 1896 phone book has them with the same number. The fire station had number 1, the Royal Infirmary 2, and the police station (they must have been late getting in the queue) had 79! The highest number listed was 312, so the whole city probably had fewer phones than the hotel mrs.tenacious mentions.