Binance officially migrated the BNB token, which was originally an ERC-20 token on Ethereum, to its native Binance Chain on April 23rd, 2019. Binance no longer supports the withdrawal of ERC-20 BNB tokens on the exchange, but continues to support the token swap from ERC-20 token to the Binance native chain. Binance Chain BNB tokens fall under the BEP-2 token standard for the blockchain.