I would think so. It accommodates paper with the following widths: letter, A4, B5, and A5. It will scan up to 14.16" in length. Up to 10 custom sizes can be entered from 2 - 8.5" wide and from 2 - 14.16" long.
Yes it will....the paper sizes are of no consequence. I have loaded a number of different lengths and widths in the same batch and it just goes through them fine. The one caveat is that the paper would have to be reasonably centered in the Automatic Document Feeder (ADF) so that the roller can grab the next sheet.
Your biggest issue will be the electric connection... plug and wiring capacity. If you have a proper UK power supply from Fujitsu and the machine is capable of handling your power (not sure if you are 225 or 110) then you should have no problem. This is a question for Fujitsu. You may need to be sure that you are getting a UK unit and not a USA unit. Once installed, it is a great machine and easy to use. It accommodates many sizes of paper as the guides are infinitely adjustable horizontally.