What Is a Post Only Order in Crypto Trading?
⏱️ 5 min read
- A post only order is a special limit order that guarantees you pay maker fees (lower) by never taking liquidity from the order book.
- It automatically cancels if it would execute immediately as a taker order, preventing accidental liquidity removal.
- Using post only orders strategically can save you 50-80% on trading fees compared to market or aggressive limit orders.
You’re setting up a limit order on Binance or Bybit, and you see a checkbox labeled “Post Only.” What’s that about? It’s not just another toggle — it’s a fee-saving tool that professional traders use to keep costs low. Sound familiar? Most retail traders ignore it, losing money on fees without realizing it. Let’s break down exactly what a post only order is, why it matters, and how you can use it to keep more of your profits.
What Is a Post Only Order and How Does It Work?
A post only order is a type of limit order that ensures your order adds liquidity to the order book instead of removing it. In simple terms: when you place a post only order, the exchange checks if your order would immediately match with an existing order. If it would, the order gets cancelled — it never executes as a “taker” trade.
Here’s the mechanics. On most crypto exchanges, there are two roles in every trade: the maker and the taker. The maker adds liquidity by placing an order that sits on the book (like a limit order at $50,000 for Bitcoin when the current price is $50,100). The taker removes liquidity by matching against an existing order immediately (like buying Bitcoin at the market price). Exchanges charge maker fees (0.02-0.10%) and taker fees (0.04-0.20%). Post only orders force you into the maker role, saving you money every time.
So if you want to buy ETH at $3,000 but the current price is $3,050, a regular limit order works fine — it sits on the book as a maker. But if you set a limit order at $3,050 (exactly the current best ask), that order might execute instantly as a taker. A post only order would catch that and cancel it, protecting you from paying taker fees.
How Exchanges Handle Post Only Orders
Major platforms like Binance, Bybit, and Kraken all support post only flags. On Binance Futures, you’ll find it as an “Enable Post Only” checkbox when placing a limit order. On Bybit, it’s called “Post Only” under order type options. The behavior is identical across platforms: if the order would be a taker, it’s rejected or cancelled.
For more on managing order types effectively, check out How to Start Crypto Trading: A Beginner's Roadmap to Your First Trade.
Why Should You Use a Post Only Order on Crypto Exchanges?
The biggest reason? Fee savings. Let’s be real — trading fees eat into your profits faster than most people realize. If you’re a frequent trader making 50 trades a day with an average position size of $1,000, the difference between maker and taker fees adds up. At 0.10% taker vs 0.02% maker, you’re saving $40 per day on those 50 trades. That’s $1,200 a month.
Beyond fees, post only orders help you maintain better order book positioning. When you place a limit order that doesn’t get filled immediately, you’re already at the front of the queue for that price level. If you accidentally use a taker order, you lose that spot and pay higher fees. Post only prevents that mistake.
Who Benefits Most from Post Only Orders?
- Scalpers and day traders — high frequency means high fee sensitivity. Every basis point matters.
- Arbitrage traders — thin margins mean even small fee differences can flip a trade from profitable to losing.
- Anyone using limit orders near the current price — if you’re placing orders close to the spread, post only prevents accidental taker fills.
I remember a friend who traded ETH on Binance for months without knowing about post only. He was paying taker fees on about 30% of his limit orders — orders he thought were maker trades. Once he enabled post only, his monthly fees dropped by over 60%. That’s real money.
How Does a Post Only Order Compare to Limit and Market Orders?
Let’s put it side by side. A market order always takes liquidity — you buy or sell instantly at the best available price. You’re always a taker, always paying the higher fee. A standard limit order can be either a maker or taker, depending on whether it fills immediately. A post only limit order is specifically designed to only be a maker, cancelling itself if it would be a taker.
Here’s the key difference: with a standard limit order, you might think you’re being a maker, but if your price matches the current best bid or ask, you become a taker without realizing it. Post only removes that ambiguity. It’s like having a safety switch that says “I only want to pay maker fees, no exceptions.”
For a deeper dive into market orders and their risks, see How to Start Crypto Trading: A Beginner's Roadmap to Your First Trade.
When Post Only Orders Fail
There’s a catch. If the market moves fast and your post only order keeps getting cancelled because it would take liquidity, you might miss entries entirely. This is especially common during high volatility — like when Bitcoin jumps $500 in seconds. Your post only order at $50,000 might get cancelled 10 times in a row because the price keeps hitting your level instantly.
In those moments, you have a choice: switch to a standard limit order (risking taker fees) or use a market order (guaranteed taker fees). Post only is powerful, but it’s not a one-size-fits-all solution.
When Should You Avoid Using a Post Only Order?
Post only orders aren’t always the right move. Here are situations where you should skip them:
- During fast-moving markets — if you need to get into a position quickly, post only will keep cancelling your orders. You’ll miss the move.
- When using stop-loss or take-profit orders — these are usually designed to execute immediately when triggered. Post only would defeat their purpose.
- On low-liquidity pairs — if the order book is thin, your limit order might sit unmatched for hours. Post only doesn’t change that, but it means you’re not getting filled at all.
Think of it this way: post only is for patient traders who want to save fees. If you’re chasing momentum or need instant execution, it’s the wrong tool. But for 80% of limit order scenarios, it’s a no-brainer.
According to Investopedia, post only orders are widely used in traditional finance as well, particularly by high-frequency trading firms who optimize every fraction of a cent in fees.
FAQ
Q: Does a post only order guarantee I’ll get filled?
A: No. A post only order only guarantees you’ll pay maker fees if it fills. It doesn’t guarantee execution. If the price never reaches your limit, the order sits on the book indefinitely (or until you cancel it). During fast markets, it may keep cancelling itself without ever filling.
Q: Can I use post only orders on spot markets too?
A: Yes. Most major exchanges support post only orders on both spot and futures markets. The fee structure is usually similar — maker fees are lower than taker fees on both. Check your exchange’s fee schedule, but generally the same logic applies.
Q: What happens if my post only order is partially filled?
A: If your order gets partially filled as a maker (because part of it matched with incoming orders), the remaining portion stays on the book as a post only order. The filled portion paid maker fees. The unfilled portion continues to wait for a match.
Final Thoughts
Let’s recap the key points:
- Post only orders force your limit order to be a maker, saving you 50-80% on trading fees.
- They automatically cancel if they’d execute as a taker, preventing accidental fee spikes.
- Use them for patient limit orders near the current price, but skip them during fast markets or when you need instant execution.
Start enabling post only on your next limit order and watch your fee bill shrink. For smarter trade execution with real-time signals, check out Aivora AI Trading signals.