When you have to enter an address lookup table on Amazon or another website (talking about UK specifically) where does the site get that info from? Is there a .gov table of everyone's addresses or does the website themselves have a database all them all.
Yes in the UK the Royal Mail has a PAF, Postcode Address File, that they license out for use to address validation providers. You can read more about it on the PAF website
There are similar databases in other countries as well