The municipality was established on 18 May 2014 by merging the existing Rampur Birta, Malhaniyakhori, Radhopur, Ramnagar Mirchaiya, Phulbariya, Sitapur PraDa and Maheshpur Gamharia Village Development Committees.

[3] This is one of the main business markets for Katari and the southern part of the Siraha district.

Mirchaiya is considered as a trade and economic center of Sagarmatha zone and some part of Udayapur district after lahan.

Residents of hilly and mountainous regions of Sagarmatha zone are largely dependent on Mirchaiya for their supplies.

Since, this place is totally routed by From Mahendra Highway is directly linked from capital, Kathmandu by Tata Sumo or Hiace (following the KTM-Bardibas road 6–7 hours) | following Chitwan it will take 10–11 hours or by domestic flight to either Janakpur (65 km west of Mirchaiya) or Biratnagar (145 km east of Mirchaiya) and continuation by local bus.