If I need to transfer from London, do I need a UK visa?

Generally speaking, a transit visa is required for transit from London, but if you are going to New York, USA, it means you have a US visa. However, the British visa stipulates that if you hold a US visa, you do not need to apply for one. With a transit visa, you can transfer directly.

At present, the result of applying for a British visa can be obtained in two days, and it does not take as long as 30 working days. Moreover, if the following conditions are met, you can transfer directly in the UK without applying for a visa.

(1) Go directly (or transfer via a reasonable route) to Australia, Canada, New Zealand or the United States, and hold a valid visa for that country

(2) Hold a valid visa for Australia, Canada, Traveling directly (or via a reasonable route) to the UK with a valid New Zealand or US visa?

(3) Traveling directly (or via a reasonable route) from Australia, Canada, New Zealand or the US to the UK and are not far from you The last time you entered Australia, Canada, New Zealand and the United States with a valid visa is no more than 6 months ago.

(4) Hold a permanent residence permit issued by Australia or New Zealand?

(5) Hold a valid uniform-format residence permit issued by a European Economic Area country or Switzerland?

(6) Hold a valid permanent residence permit issued by Canada after June 28, 2002?

(7) Valid unified form of entry into a European Economic Area country or Switzerland Type D visa

(8) Do you hold an Irish biometric visa and an onward flight ticket to Ireland*** and the country?

(9) Are you traveling from Ireland*** and the country? Traveling to the UK and it has been no more than 3 months since you were last admitted to or arrived in Ireland on an Irish biometric visa

(10) Hold a valid permanent residence permit issued by the United States on or after April 21, 1998 Card?

(11) Hold a valid I-551 temporary immigrant visa issued by the United States (stamped versions will not be accepted)?

(12) Pass I-797 Letter confirming extension of expired I-551 permanent residence card issued on or after April 21, 1998 in the United States?

(13) Hold separate U.S. Immigration Form 155A/155B (attached to the sealed On a brown envelope)

Reference materials: Applying for a British visa in China - Eligibility & Materials - GOV.UK