Simply including paragraphs within the website which indicate to visitors and to the search engines that the company is based in London and operates throughout the South (Essex, Surrey, Sussex and Herts) will help to boost the rankings within Google, Bing and Yahoo.
Making the telephone number searchable too is another trick as is making sure the company address and postcode are included.
Meta tags, particularly page title and description, can also be used as they are often the first indicator to customers as to where the company is based.
If you would like me to review your website, please call O7767600039.