You’re not permitted to take more than 500 Nafka (ERN) out of Eritrea. Under 18’s aren’t entitled to hold any amount of Nakfa. If you’re exiting Eritrea and you hold in excess of the 500 maximum limit, it will be confiscated and where the amount exceeds ERN 5,000 you may face prosecution leading to a heavy fine, as well as a delay to your departure.
The economy is completely cash-based. There are no credit card or ATMs facilities in Eritrea. You’ll need to pay for everything in cash. Most hotels in Eritrea will require you to settle your hotel bill in US Dollars. It’s illegal to use foreign currency to make purchases except at a limited number of officially-recognised hotels. You should get a receipt for any such purchases.
The currency in Eritrea is the Nakfa. Nakfa aren’t convertible outside Eritrea. You should convert any excess Nakfa back to hard currency at one of the ’Himbol’ exchanges in town, as there are limits to what can be converted at the ’Himbol’ branch at the airport. You will need the original currency transaction receipt. The Nakfa is currently pegged at the rate of 15 Nakfa to one US dollar.