Do I need planning permission for a shop sign in West Yorkshire?

Frequently, yes. Illuminated signs, signs above certain sizes, and any signage on a listed building or within a conservation area generally require advertisement consent from the local authority, plus listed building consent where applicable. Calderdale and Kirklees contain unusually large conservation areas, so this catches many Halifax, Hebden Bridge and Huddersfield premises. Consent typically takes around eight weeks, which means it belongs at the start of a signage project rather than the end.