Why Does My Wallet Show a Failed Transaction on Polymarket?

28 September 2026

A failed transaction on Polymarket almost always comes down to one of a handful of causes: insufficient funds for gas, a price impact or slippage limit that was exceeded, an expired approval, a nonce conflict, or a wallet signature that was rejected or timed out. The block explorer will show the transaction as reverted, but the reason is rarely a problem with Polymarket itself. It is usually something on your side, or a condition you set that the market no longer meets.

Here is how to work through it.

Start With the Obvious: Gas and Balances

The first thing to check is whether your wallet has enough native token to pay for the transaction. Polymarket runs on Polygon, so you need POL (formerly MATIC) for gas. If your balance is near zero, the transaction will fail immediately, often before it even reaches the mempool.

A related but less obvious issue: if you are using a smart-contract wallet or a wallet that abstracts gas fees, the wallet itself may be the one paying gas, and it can run out. Check the wallet's own balance, not just the balance of the account you think you are trading from.

Slippage and price impact limits

Polymarket trades execute against an automated market maker or an order book, depending on the market. If you place a market order, the interface calculates an estimated fill price. That estimate can be wrong by the time your transaction lands on-chain, especially in fast-moving markets. If the actual price moves beyond your slippage tolerance, the transaction reverts.

The fix is not to set slippage to an absurdly high number. It is to understand that a revert here is the system protecting you from a bad fill. If you absolutely need the trade to go through, use a limit order instead, or split the order into smaller pieces.

Approvals: old and stale

Polymarket uses an approval mechanism for USDC, the collateral token. If you previously approved a spend limit and then that approval was used up, or if you approved a different amount than what you are now trying to spend, the transaction can fail.

Some interfaces handle approvals automatically. Others do not. If you see a failed transaction that mentions "allowance" or "approve" in the error log, you need to reset the approval. Go to the USDC contract on Polygon, revoke the existing approval for the Polymarket exchange contract, and approve again with the new amount.

Nonce Conflicts

If you send multiple transactions in a row and one of them is stuck or slow, the others can fail because they share the same nonce. This is common with wallets that queue transactions locally. The wallet thinks it is sending transaction number five, but the network has already seen a different transaction five.

Check your wallet's transaction history for a pending transaction that never confirmed. Cancel it or speed it up, then retry the failed one. Do not just resubmit blindly; you will get the same nonce error.

Signature requests that time out

Polymarket sometimes asks for a signature, not a full transaction. Signatures are used for order book trades and for some settlement operations. If you take too long to approve the signature, or if the session expires, the order is cancelled on the backend. The wallet may show a "failed" state, but really the order never existed.

Retry the order and approve the signature promptly. If the interface keeps asking you to sign and then failing, clear your browser cache or switch to a different browser. Some wallet browser extensions have known issues with repeated signature requests.

What the error messages actually say

When a transaction fails, the block explorer will show an error reason. Common ones include:

• execution reverted - the contract logic rejected the transaction. This covers slippage, expired approvals, and invalid order states.
• insufficient funds - you do not have enough POL or USDC.
• nonce too low - a nonce conflict.
• user rejected - you clicked cancel on the wallet prompt, or the signature expired.

The error message often appears in the wallet itself, not on Polymarket's site. If you are not seeing it, look at the transaction on Polygonscan. The "Logs" and "Internal Txns" tabs will show more detail.

When it is not your fault

Sometimes the failure is on the market side. If a market has resolved and settlement is in progress, the contract may reject trades or claims until settlement completes. If an oracle is in a dispute window, trades on that market can be paused. These failures are temporary and will clear.

Rarely, a market contract itself can be paused or deprecated. Polymarket has retired old markets and moved liquidity. If you are trading a very old market, the contract may simply no longer accept orders.

A Practical Checklist

Work through these in order:

1. Confirm you have POL for gas. Add some if you do not.
2. Check the transaction on Polygonscan. Read the error reason.
3. If the error mentions allowance, revoke and re-approve USDC.
4. If the error mentions slippage, adjust your order type or tolerance.
5. If the error mentions nonce, clear pending transactions in your wallet.
6. If the error is a signature issue, retry and approve quickly.

Most failed transactions on Polymarket are resolved by one of these steps. If none of them work, the problem may be with the market's contract state, which is worth checking on the market page before you spend more gas trying to force a trade through.

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