How to find out online who used to live at an address?

Hello, I have a customer that has a lot of addresses for which they need to find out the names of the people that used to live there before the current occupants going back roughly 20 years or so (i.e. not very long). Most tracking companies / services (e.g. Experian etc) use a name and an address... what we need is to be able to find all the recent names for a particular address. We need the solution to be quick, cheap and something that can be scripted / automated... we need the research doing first i.e. how to get the information online and from which sites etc... we do not need any scripting etc done... this is just a research project... as an example then... why not give me the names of all the recent people that have owned any random UK address that you want to try? All properties the client wants to research are in the UK, the address details they have are house number and postcode. IF you could also find a way to also deliver the CURRENT addresses of the people that used to live at an address previously then that would be a distinct advantage too - this is not essential but would definitely make your bid much stronger! Look forward to your bids, thanks!