Understanding Post-Only Orders: Controlling Your Trading Fees

When you’re trading at scale or scalping across tight spreads, every fraction of a fee matters. That’s where post-only orders come in. This order option, available as an add-on to Limit and Conditional Limit Orders, is designed to ensure your orders land in the order book rather than execute immediately—which means you pay the maker fee instead of the taker fee. This feature is supported across Spot Trading for Unified Trading Account users, plus Perpetual and Futures Trading for both Standard and UTA users.

The Fee Advantage: Why Post-Only Matters

The core benefit of using post-only is straightforward: control over your costs. By activating this option when placing a limit order, you guarantee that your order will enter the order book, which qualifies you for the lower maker fee rate. For high-volume traders and those executing frequent, smaller positions, this difference compounds quickly. The system automatically rejects any limit order that would execute immediately upon placement, protecting you from accidentally paying the higher taker fee when you were expecting to post liquidity.

How Post-Only Works in Practice

Consider a scenario in a fast-moving market. You place a limit buy order for 100,000 BTCUSD at USD 9,000 when the best ask is showing 9,001. But by the time your order reaches the matching engine, the market has moved sharply—the best ask is now 8,995. Without post-only enabled, your limit order would immediately execute as a market order, filling you all the way down to your limit price and charging you the taker fee. With post-only active, the system recognizes that your order would execute instantly and cancels it instead. You avoid the unexpected taker fee entirely.

Choosing Post-Only vs. Standard Limit Orders

The decision between post-only and standard limit orders depends on your strategy. Standard limit orders give you flexibility—they’ll execute if market conditions match your price, but they might trigger a taker fee if the spread moves against you. Post-only takes a stricter approach: your order succeeds only if it adds liquidity to the book. This makes it ideal for traders managing their cost structure and those relying on specific Time-In-Force strategies like GTC, IOC, or FOK to execute their trading plan. For large traders sensitive to fee impacts, post-only transforms how you manage execution costs across volatile periods.