All companies in the UK must clearly state the company registration number, place of registration, registered office address and if the company is being wound up on all of their websites.

A common place to put this information is in the 'About us' or 'Legal info' page of the site - it does not have to appear on every page.

Sourced From:
http://www.businesslink.gov.uk/bdotg/action/detail?r.s=sc&r.l1=1073861197&r.lc=en&r.l3=1075384855&r.l2=1074448623&type=RESOURCES&itemId=1075384905