However, a prerequisite for buying BTC is that you have to have a wallet from which you can directly deposit the BTC after the cash purchase. Yes, it is possible to buy less than one bitcoin. Coinmama, on the other hand, supports Bitcoin, litecoin, ether and cardano. This is a special feature to CEX. Giving our proof of ID and address is okay. However, when clients use credit cards in purchasing Bitcoin, they elude the monitoring system as credit money is usually legitimate, they then service their loans with the laundered money and the cycle continues. The best way is to read through the description for each exchange.