Travelling from the uk to Thailand in December, can I apply to the Thai embassy in the uk for a 30 day visa extension making a 60 day visa in oct/ nov before my arrival in December??????
TLDR : Answer Summary
You cannot apply for a visa extension before entering Thailand. The Thai embassy in the UK only issues visas, such as a 60-day tourist visa, which you can obtain prior to your travel. Extensions must be applied for in person at a local immigration office in Thailand after you have entered the country.