How to Pay Gas on Both Sides of a Mantle Bridge

To move assets between Ethereum and Mantle, keep ETH on Ethereum for the transfer and MNT on Mantle for transactions after arrival. Gas is the fee a network charges to process a transaction. The two balances serve different networks, so one cannot cover the other.

The steps and costs depend on what you send and which way you travel. For a fuller look at when to swap around a transfer, see this mantle bridge guide. The basic gas plan is simpler: have the source chain’s fee token ready before you sign, and arrange destination gas before you need to act there.

What token pays gas on Ethereum and Mantle?

ETH pays gas on Ethereum, while MNT pays gas for transactions on Mantle. Mantle’s official bridge offers a “Get Gas” option that opens Mantle Refuel, which lets users get MNT using tokens on another chain. The bridge and Refuel are separate steps: check the amount you will receive and the fees shown before confirming.

If you send an ERC-20 token, such as a stablecoin, the wallet may ask you to approve the bridge to use that token before you deposit it. Approval is a separate Ethereum transaction, so it can mean two gas payments in ETH: one to approve and one to deposit. A deposit of native ETH does not need that token approval. In either case, keep enough ETH for every transaction the wallet asks you to sign.

How do you prepare gas before a bridge transfer?

First, check the source wallet’s ETH balance. Then decide how you will get MNT onto Mantle. You can arrange MNT in the destination wallet before bridging, or use Mantle Refuel after arrival if its supported assets and route suit your transfer. A balance of bridged ETH or a stablecoin on Mantle does not by itself pay fees in MNT.

• Check that the wallet address is the same on the source and destination networks.
• Leave ETH on Ethereum for any approval and the deposit transaction.
• Plan a small MNT balance on Mantle for your first transaction there.
• Review the displayed fees and the amount to be received before signing.

Do not spend the whole MNT balance on the first action. A swap, another approval or a withdrawal can require another Mantle transaction, each with its own fee. Keep enough for the next step you expect to take.

What gas do you need when moving back to Ethereum?

A withdrawal starts with a transaction on Mantle, so you need MNT there to initiate it. If the route later asks you to claim funds with a transaction on Ethereum, that transaction needs ETH in the wallet that makes the claim. Check the bridge’s status and instructions, and keep both balances available until the funds arrive.

The practical rule is to budget by network and by step: ETH for actions on Ethereum, MNT for actions on Mantle. That prevents a common snag: funds arriving on the destination chain while the wallet lacks the token needed to move them.