Please, read carefully if you intend visiting the United Kingdom after April 24th, 2015.
A summary of the key changes for visitors from 24 April 2015
The Statement of Changes in Immigration Rules, HC 1025, laid before Parliament on 26 February 2015, consolidates the Immigration Rules for visitors into a new Appendix V to the Immigration Rules. The new rules for visitors take effect from 24 April 2015, with some transitional provisions as outlined in the Immigration Rules, Part 2.
The changes aim to rationalise the rules for visitors, making them largely self-contained within Appendix V, simplifying the language and reducing the number of visitor routes so that some visitors now have more flexibility in the range of activities they may undertake while in the UK.
The new rules will be accompanied by new sets of guidance, due to be published on or shortly after 24 April 2015.
http://www.lexisnexis.co.uk/pdf/practice_note_immigration_rules_for_visitors.pdf