Kathmandu District Court sent them to prison in the two-month-old case, according to Kathmandu Metropolitan Police Circle.
The four were identified as Masud Aalam (37), a resident of Karachi, and three Nepalese men - Arjun Lamsal (31) and Sohel Khan (28) and 40-year-old Yunus Ansari, also known as the the kingpin of fake IC smuggling in Nepal.
They were arrested on January 23 from a guest house at Thamel, a tourist hub near Kathmandu, along with 3,500 fake notes of Rs 1,000 denominations.
Ansari was freed from Kathmandu Central Jail just six months ago after serving a three-year sentence on a similar charge.