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Every perpetual order is checked against the contract’s rules before it’s accepted. An order that breaks any rule is not created — the platform blocks it at submission, so it never enters the order book or your Order History. If you’re unable to place an order, one of the rules below is the most likely reason. This page lists the rules and the current values for each perpetual contract.

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Order Validation Rules

The price band is why a limit order placed far from the current price can be blocked even when its price is otherwise valid. It prevents fat-finger orders and trades at unrealistic prices.

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Contract Specifications

The maintenance margin rate (MMR) is the fraction of position notional you must keep to avoid liquidation. See Margin & Leverage and Liquidation & Mark Price for how leverage and maintenance margin affect your positions.

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Market-order slippage tolerance

A market order opens immediately at the best available price, so the fill price can differ from the mark price shown at submission. To stay funded if it fills at a worse price, a market order reserves about 5% extra initial margin on top of the normal requirement.

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Worked Examples

You place a limit order on BTCUSDT-PERP at 60,000.05. The tick size is 0.1, so the price must end at a multiple of 0.1 (e.g. 60,000.0 or 60,000.1). You won’t be able to place it — round your price to the tick size and try again.
With BTC trading around 60,000, you place a limit buy at 20,000 — below 50% of the reference price (30,000). The order falls outside the price band, so it’s blocked. Place the order within the allowed range around the current price.
You try to open a 0.0005 BTC position on BTCUSDT-PERP. The minimum order size is 0.001 and the step size is 0.001, so 0.0005 is both too small and not a valid increment. Use 0.001, 0.002, and so on.