Spot Trading
Post Only, IOC and FOK on Binance: Order Execution Explained
Understand maker-only execution, immediate partial fills and all-or-none immediate orders with a simple liquidity example.
These settings do not predict price direction. They control how an order enters the book, how long it remains, and whether partial execution is allowed.
| Setting | Core rule | Possible result |
|---|---|---|
| Post Only | Must add liquidity as maker | Cancelled/rejected if immediately marketable |
| GTC | Active until filled or cancelled | Can rest and partially fill |
| IOC | Fill available quantity now; cancel rest | Partial fill allowed |
| FOK | Fill the full quantity now or cancel all | No partial fill |
Post Only is a maker constraint; GTC, IOC and FOK are Time in Force choices, although interfaces may group them nearby.
1,000 USDT example
Assume only 400 USDT is offered inside your acceptable price:
- IOC fills 400 and cancels 600.
- FOK cannot fill all 1,000, so it cancels the entire order.
- GTC limit fills 400 and leaves 600 resting.
- Post Only refuses to enter if your price would immediately take the 400.
When each fits
Post Only: you require maker execution and accept cancellation or missed price.
IOC: take current liquidity now without leaving a remainder.
FOK: the full size is required immediately, often for complete hedge execution.
GTC: a regular patient limit plan that accepts partial fills.
Common mistakes
- Assuming Post Only guarantees the lowest final fee; account rates still apply.
- Treating a partially filled IOC as fully cancelled.
- Calling an FOK cancellation an error when book size was insufficient.
- Forgetting a long-lived GTC order that later executes.
- Assuming every market and symbol supports identical parameters.
See Binance's Time in Force guide and our fee reduction guide.
⚠️ Advanced execution parameters do not decide whether the trade itself is sensible.