(3 hours ago)Sland2000 wrote It all made so much sense then!

The 4xx series was Northumberland. Some of the existing services in the county are remnants of that system (419, 460, 472, 464, 473, 477). At the beginning of three-digit numbering, the 308 was actually 408.

8xx was allocated by Northumberland CC to the many independent operators, the only remnants of which are the 888 and 889. Until quite recently the Otterburn - Newcastle service was numbered 808. Northumberland also numbered its school day services 9xx. These services were open to the general public.