Inner line permit office | Checkpoint

You can get your inner line permit here to enter Sikkim. 8am to 8pm.
You will need a copy of your passport and visa along with a passport size photo. You can get these at a nearby shop just on the other side of the border.
Initial Permits are for about 5-7 days, extension is supposed to be possible.
There is no fee for the permit, it took about 15 minutes to complete and was very straightforward process.

We had heard that it can be difficult to get a Chinese visa if you have a Sikkim stamp in your passport not sure how true this is but we asked for them to stamp a piece of paper and staple it into our passport after explaining this to them they where happy to do this.

As a foreigner, as soon as you enter Sikkim you need the inner line permit (ILP). Otherwise your illegally there and no accommodation will host you. Valid for areas (see picture). In Gangtok you can get the protected area permit (PAP) for some more areas. But most border places are off limits for foreigners.