Unfortunately the Travelcard is not commonly accepted in Nepal as most merchants do not accept MasterCard (even if they say so). Visa is commonly accepted though, so I propose you bring both your Travelcard and a Visa card as a backup.

In Kathmandu it's relatively common to pay by card, but remember that the average amount for food, drinks and other things will be relatively low. As a result, most merchants will ask you if you can pay by cash.

If you want to go to an ATM, keep in mind that most charge a 500 Nepali rupee fee (~4 EUR) per transaction for foreign cards, including the Travelcard, on top of regular transaction fees.

Also: they drive on the left, plugs are varied but usually British or European, and I strongly recommend to get a local simcard as they're not expensive and very useful if you'd like to book a taxi for instance without wanting to pay the tourist price. There are a few apps that are similar to Uber and you can only register with Nepali numbers. Make sure to check the coverage of the different providers because some don't cover the full country.

Taxi apps: Pathao and Sarathi
Maps in remote locations: Maps.me (based on GPS so reliable even if you don't have a connection; make sure to download maps in advance)

@Navy-Falcon#131687 If you use an ATM keep in mind that the maximum amount you can take out is sometimes 10.000 rupees. The transactionfee of 500 is a lot. Some banks have higher maximumamounts (for instance Nabil Bank has a max of 35.000 with the same transaction fee).

If possible go to an ATM lounge. They are safe and you have a higher chance of an ATM with a higher maximum amount.

Perfect works