Polygon bridge deposits finish only when the bridged asset appears in your Polygon PoS balance, after any needed approval and the Ethereum deposit. The Polygon bridge locks assets on Ethereum before Polygon validators relay a state sync that credits Polygon, so Ethereum confirmation is not arrival. For ETH, you can bridge to Polygon without approval.
Approval and Deposit Are Separate Ethereum Transactions
For an ERC-20, approval grants spending permission; the separate deposit locks the tokens on Ethereum. To bridge tokens to Polygon, start with a supported token in MetaMask and enough ETH on Ethereum for gas. Connect to Polygon Portal, set the direction from Ethereum to Polygon PoS, then select the asset and amount. Review the receiving address: it should be your own wallet address. MetaMask uses the same address on both networks, but each network keeps its own balance.
The Portal may request approval before offering the deposit. Approval sets an allowance, giving the bridge contract permission to spend the amount you authorize. A confirmed approval moves no tokens. If an adequate allowance already exists, the Portal may go straight to deposit. For a single transfer, approving only the needed amount limits any permission left afterward.
- Approval confirmation: The ERC-20 contract records spending permission on Ethereum. Wait for confirmation before expecting the deposit prompt.
- Deposit confirmation: The separate deposit transaction locks the asset in Ethereum bridge contracts. This is the commitment that starts the transfer.
ETH is the boundary case: native ETH is not an ERC-20, so it needs no allowance transaction. Select ETH, leave enough for Ethereum gas, and sign the deposit. No approval prompt is expected.
Ethereum Confirmation Starts a Separate Polygon State Sync
A confirmed deposit locks the Ethereum asset, but it does not instantly change your Polygon PoS balance. The deposit emits an Ethereum event. Polygon validators relay that event through a state sync, which tells the Polygon side to mint the mapped token to your address. This is why the Polygon bridge can show a confirmed Ethereum transaction while the destination balance still reads zero.
These stages depend on one another. The deposit must enter an Ethereum block and receive the confirmations the bridge waits for; only then can the state sync carry its message and the Polygon token be minted. Arrival time varies with Ethereum inclusion and confirmations, plus state sync processing. The Ethereum receipt proves the deposit stage succeeded, not that the entire transfer ended.
Once the Ethereum deposit confirms, no second deposit signature is needed on Polygon for this direction. Wait for the destination update instead of sending another transfer because MetaMask still shows the source network.
The Polygon PoS Token Balance Is the Completion Signal
The deposit is complete when the mapped asset appears in your address’s balance on Polygon PoS. Switch MetaMask from Ethereum to Polygon PoS and look for the token there. The bridged asset uses a different contract address on Polygon, called its child token contract. A Polygon PoS block explorer can show your balance under that contract even if MetaMask has not listed it. Add the Polygon contract address as a custom token in MetaMask to display the balance.
This matters especially for an ETH deposit. On Polygon PoS, bridged ETH appears as a token such as WETH, separate from the network’s native gas asset, POL. Looking only at the native balance can miss a successful arrival. The same address can hold the bridged token while MetaMask still shows Ethereum or has not listed the Polygon token.
To use the asset in a Polygon app, its balance must have arrived and your wallet must be on Polygon PoS. You also need POL there for app transaction gas; ETH left on Ethereum cannot pay it. The Ethereum receipt proves your asset entered the bridge, while the mapped Polygon balance proves it reached the address where you can use it.
Related Questions About the Transfer
How Do I Withdraw Assets From Polygon to Ethereum?
Withdrawal starts with a burn on Polygon PoS. After the withdrawal is included in an Ethereum checkpoint, you claim the released asset on Ethereum. Keep POL for the Polygon transaction and ETH on Ethereum for claim gas. Depositing does not create an automatic Ethereum payout.
Why Is My Deposit Still Pending?
The pending stage determines what you are waiting for. In Polygon Portal’s transaction status, an unconfirmed approval means only the allowance is waiting. A pending Ethereum deposit means the asset has not yet been locked. If the deposit has confirmed but the Polygon balance is absent, the state sync and mint may still be in progress.
Is This Bridge Safe to Use?
Safety depends on the bridge contracts and the permissions you sign. Before authorizing either transaction in MetaMask, verify that Polygon Portal shows the supported asset, the Ethereum-to-Polygon PoS direction, your own receiving address and the intended approval amount. Contract and state sync risks remain even when those details match.
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