BitMEX spot fees are calculated based on your fee tier. Taker fees apply to orders executed immediately at market price, while maker fees apply to limit orders that add liquidity. The system locks the order amount plus the highest applicable fee before execution.
What is the difference between taker and maker fees?
Taker fees
Taker fees are charged when you place an order that is executed immediately at the market price. These fees apply because you are “taking” liquidity from the order book. The fee amount is calculated based on your fee tier. BitMEX assumes the highest fee for your tier and locks the total order amount plus fees before execution.
Maker fees
Maker fees are charged when you place an order that is not executed immediately but instead adds liquidity to the order book. These fees apply when you are “making” liquidity by placing a limit order. The fee amount is likewise calculated based on your fee tier, and BitMEX locks the total order amount plus fees upfront.
How does fee locking work in practice?
Before any spot trade is submitted to the matching engine, BitMEX verifies that your wallet holds enough funds to cover both the trade value and the maximum possible fee for your tier. The system locks this combined amount, ensuring the order can be fully settled regardless of the final execution price. Fee locking prevents orders from failing mid-execution due to insufficient balance, which protects both the trader and the order book from partial fills caused by funding shortfalls.
Suppose you place a buy order for one XBT at a limit price of 40,000.00 USDT. At a fee rate of 0.1%, you would need at least 40,040.00 USDT in your wallet to submit the trade. The additional 40.00 USDT represents the locked fee amount. If the actual fee when the order is filled turns out to be lower than the initially assumed fee, the difference is refunded to your wallet automatically. For example, if your order fills as a maker trade at a lower fee rate, the excess locked amount is released back to your available balance immediately after settlement.
Fee locking applies to both buy and sell orders, and the locked amount is always calculated using the highest fee rate applicable to your current tier.