According to the new rules and regulations it is necessary to obtain a TCR (Trekking Certificate Registration), which means following:
Before starting on ANY trek in Nepal, independent of the other permits, you will need to:
1. Register with TAAN
(Trekking Agency
Association of Nepal) or any other registered Company.
2. Obtain the TCR and then obtain the Permit (if
needed)
3. Carry the
TCR with you at all times during your trek.
The idea is not to harrass visitors (which inevitable will happen) but to keep track of people wondering into the hills and dissapearing or staying too long (which has happened before).
Overall the precedure wont cost much money (similar to inner line permits in Ladakh) and time but will help the tracking of people.