One way car rental to and from an airport in the UK has been an issue for some time regarding one way supplements being added to the hire charge. There is, however, one company who are relatively lower profile than others but whose costs for the facility are generally less expensive than most.
It is a facility of Europcar and the simplest way to access the site is by googling Europcar Airport Connect, ( it is important not to simply google Airport Connect as this will lead you to a plethora of unrelated more expensive sites. You need to prefix your search with Europcar),
However, for the general hire of a vehicle to drop off at the same location as pick up it seems that rentalcars.com are about the most competitive at the moment with travelsupermarket.com also on occasion coming up with a realistic deal.
I hope that this information might prove to be useful and cost saving
Info supplied by PT.