Some blockchains, like the ethereum blockchain, support a specific type of transaction called a smart contract. Unfortunately, since smart contracts are technically different from 'regular' currency transactions, some wallet providers do not support them. In these cases, one of two things will happen:
- Despite being confirmed on the blockchain, the coins may never arrive to your wallet, OR
- Your wallet provider needs to manually approve the transaction, causing unpredictable delays
Because of this, it's crucial that you check with your wallet provider prior to placing an ethereum order on Coinmama. Here are some of the known providers with this issue:
- Bitfinex (read their announcement)
- CoinExchange.io (takes a 10% fee for manually confirming)
To learn more about smart contracts, click here.