For what it's worth, found that Aberdeen paper from 2005 which discussed the practice of spouses using taxis and PHVs (or PHCs in Scotland, strictly speaking, since the legislation refers to a private hire *car*). Couldn't copy the text from the original document (seems to be copy-protected in some way), so this is just the most relevant extracts, because I couldn't be bothered typing the whole lot out (in fact if I'd just started typing it rather than fannying around the other night trying to find a way of copying it I could have typed the whole lot in less time).
Aberdeen City Council, in 2005, wrote:
The practice in Aberdeen has been that it was permitted for the licensed vehicle to be driven by another person, provided it was for domestic purposes. Condition 30 for taxis and Condition 25 for private hire cars expressly state this.
Grampian Police have indicated that they would take no action against a spouse driving a taxi or private hire car for domestic purposes, provided insurance was in place. The Taxi Inspector has advised that this appears to be the position accepted by most police areas in Scotland. The Corporate Director is of the opinion that this is a very important issue, given the number of saloon taxis and private hire cars in operation in Aberdeen, and in probably other more rural areas of Scotland, with dual roles as work and domestic vehicles, and the position should be clarified as soon as possible.
The trade representatives on the Review Group have expressed surprise as to the apparent illegality of a practice that has been widely accepted over many years by the police and the Taxi Inspector. They have also expressed surprise that their insurers, some of whom are based in England and specialise in insuring taxis, have been willing to grant insurance. They would have thought that the insurers would be would have been aware of the legal position.
The Corporate Director was clearly of the view that the practice was illegal, but wanted the Scottish Executive to clarify the matter nationally before taking any action. This was in the Recommendations section of the paper:
Aberdeen City Council, in 2005, wrote:
Notes the Corporate Director of Legal and Democratic Services' opinion that taxis and private hire cars can only be driven by licensed taxi drivers or private hire car drivers (as the case may be) and should not be driven at any times by spouses or other persons, unless they are licensed taxi and private hire car drivers, for social and domestic purposes.
Instructs the Corporate Director to take no action in relation to this matter at this time but to write to the Scottish Executive so that this important matter can be clarified at a national level.
I'm not sure if the matter was ever clarified, though.