Want to avoid last-minute ATM runs. Do most hostels in Comoros take card payments at check-in
Forget about paying with a card. The financial infrastructure here is still developing, and you will find that almost all small businesses and hostels are cash-only. Even if a place could accept a card, they would likely charge a hefty fee. You must bring Euros with you to exchange, as ATMs are not reliable. Be sure to have smaller bills as well for everyday purchases.
Definitely bring cash. The financial system is not set up for card payments. I stayed at a hostel in Moroni, and they were very clear they only took cash. The owner said that even with a card machine, the transaction fees and unreliable internet make it a hassle. My advice is to get a lot of Comorian francs when you arrive, as you will need it for all your expenses.
You'll be using cash for everything, not just your hostel. My experience in Comoros was that credit card use is virtually non-existent. I stayed at a small guesthouse in Moroni and had to pay the entire bill in cash. The best plan is to bring a good amount of Euros and exchange them at a bank like Banque de l'Industrie et du Commerce. You'll also need small bills for taxis and street vendors.
You're going to want to have a pile of cash on you. Comoros is a very cash-based society, and you will not find any hostels that take a card. The few places that have card machines, mostly larger hotels in Moroni, often only accept Visa and a few will take Mastercard. For everything else, it's cash only. You need to bring Euros with you to exchange for Comorian francs, as foreign ATMs are extremely unreliable.