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I am a Chinese passport holder currently living in the Netherlands with a Dutch residence permit. I will fly from Amsterdam to London, and immediately transit from there to Hong Kong. Lugguage would be checked through directly to Hong Kong.
According to the website, I need to apply for a UK direct transit visa.
However, I am currently holding a UK visitor visa, valid for 6 months and for multiple entry. Do I still need to apply for a separate transit visa to get on board in Amsterdam?