All foreign visitors require an Inner Line Permit (ILP) to enter Sikkim. An ILP is valid for 15 days & can be extended by the FRO (Foreigner Registration Office) for a further 15 days in Gangtok. ILPs can be obtained from all Indian Mission abroad or at New Delhi (New Sikkim House), Kolkata (Sikkim House), Siliguri in West Bengal (Sikkim Tourist Office) or Rangpo Tourist Lodge – the Gateway to Sikkim on the strength of an Indian Visa. It is always a good idea to make a photocopy of your airline tickets and of the pages of your passport / Visas that have the number, your photograph and other pertinent information. Keep the copies separate from the originals.
 

Indian Tourists do not require any permits to visit Sikkim. However, a protected area permit is required to go further up to North Sikkim, Tsomgo Lake & Nathula Pass (copy of individual proof of identification required to visit Nathula Pass 02 days prior to the day of departure) & must be arranged through a govt. recognized local Travel Agency.