Hi all, we are 3 from Australia who will be in the UK for a month Aug/Sept. We want to explore as far afield as possible, starting in London & ending at Dublin airport. Are there any companies that allow this pick up & drop off, & we will be taking it across by ferry to Ireland from Scotland. Is this a viable option or do we have to hire cars in different places? Cheapest options appreciated of course!
Yes, some would, but they'd charge an absolute fortune, as you're dehiring in a different country. Instead, consider dehiring it at the Scottish port and then boarding the boat as a passenger and hiring another car on the other side.

Thank you so much fwoggie! That's a great help. Now I need to know are there hire car companies that have pick up London, drop off Troon? & are there companies that we can pick a another car up from in Larne? Cheers.

Just a thought! You may have a better choice dropping the car at Glasgow and taking train or bus to Troon.
R

Brilliant idea - thanks Rodway. This is exactly the sort of thing we need help with! Will look in to this. Any thoughts anybody on picking up a car on the other side please? Cheers, Kazza.

Even then you'd still have the problem that Larne and Dublin are in different countries, and that tends to be expensive/problematic for car hire. Consider flying Glasgow-Dublin and taking in Northern Ireland (if that is part of your particular interest) in a round trip. Distances in Ireland, while tending to be more time-consuming than you'd think, are not so large as to make that impractical.

Things don't have lists of fixed prices posted like in the old days, it all depends exactly when you do what and when you book it. I'm just making a suggestion of what I guess would usually be rather cheaper, but these things often depend upon this that and the other that only know can know.