Entry Fee & permit are the depending on the region and its importance you need different kinds of Permits to trek in Nepal. If you are trekking in restricted areas you will need a special permit and we have semi restricted areas where you need also the special permit.
Otherwise you can trek with National park Permit or conservation areas permit. And you will need another permit called (TIMS) issued by Trekking agencies association Nepal for the welfare of the local community, trekking staff and the region itself.
Times card are required for Everest, Lang tang, Annapurna, Manaslu, Dhaulagiri region. You Will need another extra permit depend upon the region.
For the restricted areas like Upper Dolpo and Upper Mustang you need special permit and for that region you don’t need any extra permit.
For Manaslu and Kanchenjunga you will need special permit but the region is semi restricted area. For this area you need three different kinds of permit i.e Tims card, special permit and National park area permit.
The permit fee for Upper mustang and Upper Dolpo is bit expensive but it’s totally worthy.