You must arrange any visit to Bhutan through an authorised travel agent well in advance. See Entry requirements.
Britain is represented in Bhutan by an Honorary Consul. The nearest consular office is British Deputy High Commission in Kolkata. See Consular assistance.
Although there’s no recent history of terrorism in Bhutan, attacks can’t be ruled out. See terrorism
In Bhutan you should take local law and customs seriously. If in doubt, you should take advice from your tour guide. See Local law and customs
If you’re abroad and you need emergency help from the UK government, contact the nearest British embassy, consulate or high commission.
Take out comprehensive travel and medical insurance before you travel.