Currently all clients are offered the lowest commissions in the industry: 0.03% (3bp) for taker's trades. All makers get rebates of 0.03% (3bp) for their liquidity.
Takers and Makers
If you place a limit order that is not executed immediately (limit buy below the best ask, or, limit sell above the best bid), you add liquidity to the order book. If another trader hits your limit order in the order book, the resulting trade will be a maker's trade for you and you will get your 0.03% rebate.
All market, stop and market-if-touched orders remove liquidity from the market and hence pay the taker's fee. The same applies for limit orders that hit the market immediately.
If you send a limit order that executes partially upon hitting the book and then rests in the book, it's first part will be treated as taker's and the remaining part — as maker's.
Fees are paid immediately once your order is filled. The fee currency is always the quote currency of a currency pair (e.g. USDT for BTC/USDT, BTC for ETH/BTC). You can always see the exact fee you paid in the Trade History in the Terminal or Account (check the "Comm." column).
Note: Maker's rebates are not shown in the Trade History.