Sikkim is one of the most important tourism sectors in the whole of India. The state welcomes hundreds of tourists every year due to its unending beauty and magic. The Indians can visit the entire regions of Sikkim as any other Indian state but the state shares borders with China and so Foreigners must obtain Inner Line Permit (ILP) to visit Sikkim. These can be obtained from all Indian Missions, Sikkim Tourism Offices at New Delhi, Kolkata, The 30 days duration Permit is issued on the spot without any delay provided photocopies of the passport and visa along with two pass port photos of the applicants are made available. The permissible duration of the stay for foreign tourists is 30 days initially.
The State Government is authorized to extend the same by a further period of 30 days. The extension of the permit can be obtained from FRO at Gangtok and office of Superintendent of Police of the North, West and South Districts.
Sikkim Tourism Offices are at New Delhi, Kolkata, District Magistrate's Office of Darjeeling, Siliguri, and Rangpo. You can visit any of these tourism offices and register for the permit with the necessary documents required therein. It is free of cost and just takes less than twenty minutes if you have proper documents like the photocopies of your passport and visa along with the original and two of your recent passport-sized photos. The validity of the permit is 30 days which can be extended further for 30 days by the approval of the state Government.
The Inner Line Permit (ILP) can also be obtained by filling up an online application form, though it would be considered as provisional Inner Line Permit (ILP) unless you get the stamp on it at any of the border check posts of Sikkim.
Protected Area Permits (PAP) is required by those who are interested in going for trekking in the interior region of the state (Both Indians and Foreigners). It is issued by Tourism and Civil Aviation at Gangtok for specified areas, and is not given to a solo foreigner tourist. There has to be a group of more than one foreigner, who's trekking programme is arranged by a travel agency registered under the Sikkim Tourism Department.
Note: For Nathula Pass, the permit is only given to Indians.