If you mean WW2, vehicles ordered under War Office contracts were intended for the British Army and would initially at least and with very few exceptions have been despatched to British RAOC or RASC depots.
This doesn't rule out subsequent supply to other nations such as Canada or Australia etc. which would have been via these depots.
It seems to have been very rare that the Admiralty or Air Ministry took over Army vehicles. They had their own budgets and the pick of the equipment anwyway.
