Through its constituent businesses the Post Office provides communications and retail services to the public and businesses. It is one of the UK's leading businesses with a turnover of more than £6 billion a year and employs some 194,000 people. The Post Office comprises four separate businesses Royal Mail, Parcelforce Worldwide, Post Office Counters Ltd. and Subscriptions Services Ltd. This makes interesting reading. The most useful sections is the POST CODE and ADDRESS CHECKER and online ordering for stamps and pre-stamped envelopes.