You cannot incorporate a company using any name you like. Some names are prohibited (for example, those which suggest a connection with the Government or the Crown) and names will not be allowed if they are too similar to the names of existing companies.
It is a straightforward matter of a company to object to the registration of a company name which could be confused with its own name. The new rules for registration of a company namecan be found on the website of the UK Intellectual Property Office.
Companies House has a system for checking the availability of names for new companies: don't forget to check that the associated Internet domain name is avalaible as well.