Article 13 allowed for construction of a road through Sikkim and rendered all British goods duty-free, except those transhipped through the country to Tibet, Bhutan and Nepal, in which case a maximum 5% customs duty would be payable.
Pasal 13 mengizinkan pembangunan jalan melalui Sikkim dan menghapuskan cukai untuk barang Britania kecuali yang dikirim ke Tibet, Bhutan dan Nepal lewat Sikkim; barang-barang tersebut dapat dikenakan cukai hingga sebesar 5%.