Paul G wrote in
:

Potters Bar falls outside the TfL area (although there is some cross
over in the TfL funded routes also operate within Potters Bar), so
it's up to Hertfordshire County Council what the routes are called.

The 313 goes from Chingford, through Enfield, up the Ridgeway and into
Potters Bar, and according to the timetable I've just downloaded from TfL
it's "Operated by Arriva London for London Buses".

Iain