I need to find an official source for "Data Export" legislation that applies within the UK, I have searched the .GOV websites and found various pages that refer to physical item (military and dual-use) legislation but not to Digital data. I have also found references to "Data sovereignty" and "Data Residency" but these don't appear to be UK specific.
Scenario:
Company A (UK) needs to store potentially sensitive (possibly military) data which may include communications, parts diagrams, personal data etc in an online platform that can be accessed by the sales team within the UK only.
Company B (USA) offers such a platform, but may be hosting the data in datacentres in the USA, Ireland etc.
I need to find out what UK legislation covers storage location and transmission to other countries.