Yes, you need a permit to trek in Nepal. Depending on the trekking region, you may require a TIMS card (Trekkers’ Information Management System), a national park or conservation area entry permit, and in some cases, a restricted area permit. These permits help manage and protect the trails and are mandatory for most popular trekking routes. You can get them from the Nepal Tourism Board offices in Kathmandu or Pokhara, or through registered trekking agencies.