The government of UK has announced some amendments to transit visa rules, which would come into force from 1 December 2014.
According to the latest rules and regulations, individuals transiting through UK must hold a valid Electronic Visa Waiver of UAE, Oman and Qatar. Individuals can also hold either a UK visitor visa in transit visa or any other UK visa. A valid exemption document and a confirmed onward flight shows ones depart from within 23.59hrs.
For Airside Transit, nationals of Emirati, Qatari and Omani need not require a visa to transit the UK.
For Landside transit individuals should hold an Electronic Visa Waiver or UK visitor visa.
Airside Transit (you will not pass through UK border control): If you are planning to transit the UK airside, you do not need a visa to transit UK.
The decision to enable overseas individuals to transit the UK landside without possessing any visa is taken by the Border Force officer in the United Kingdom.
Individuals are not permitted to transit UK without a valid visa or EVW, if the Border Force officer considers that the individual do not meet the criteria under the immigration rules, so they might desire to apply for a transit visa or EVW prior to their travel to ensure that they are not delayed at UK border control.
Individuals travelling to Australia, Canada, New Zealand or the USA nations should possess a valid exemption document and visa of that particular nation. On the other hand, individuals travelling from Australia, Canada, New Zealand or the USA in a period less than 6 months should also possess exemption documents even if they arrived to that country with a valid visa previously.
Individuals should also hold a valid residence permit granted either by Australia, New Zealand, Canada, Switzerland and the USA.