To check who owns a website use to be very easy.  

Every website has domain name, for example, this is the part of this website  The register of the domain name is required to collect the technical and administrative contact details of the company that registered the domain.  Until recently you could ask the domain register for theses contact details.  However, over the last few years in order to conform with GDPR regulations, this information has now been obfuscated, and this is no longer a practical method.

So, your choices are now limited.

Currently the best method is to rely on the The Company, Limited Liability Partnership and Business (Names and Trading Disclosures) Regulations 2015.  This regulation requires that a Limited Liability Company mention on their website their name, their Company Registration Number and their Registered Address.  This information is usually contained in the Terms And Conditions page of the website, and that is normally linked to from a link on the footer of the website home page.  You can look up the full company details from the search page of our website using this information.