Cross-chain · Base → Polygon

Swap ETH from Base to USDT on Polygon

Swap ETH from Base to USDT on Polygon. You sell native ETH on Base and you receive Tether USDT on Polygon.

The input is Base ETH, chain 8453, placeholder 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE, visible on Basescan as the account balance. Leave a fee remainder. The output is Tether at 0xc2132D05D31c914a87C6611C10748AEb04B58e8F, 6 decimals, on Polygonscan. Polygon is chain 137. This is not Circle's native USDC at 0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359 and not USDC.e. It is not Ethereum Tether at 0xdAC17F958D2ee523a2206206994597C13D831ec7. Afterward you need POL, because USDT is not gas.

Diagram for Swap ETH from Base to USDT on Polygon
ETH leaves Base. USDT is what can arrive on Polygon.

Tether on Polygon is its own deployment

Six decimals make this USDT feel like Ethereum USDT, and the issuer is Tether in both cases. The contract addresses are not the same, and a mainnet transfer aimed at 0xdAC17 will not move a Polygon balance. Confirm 0xc2132D05D31c914a87C6611C10748AEb04B58e8F on Polygonscan. Tether can still freeze listed addresses. A hop from Base does not remove that rule.

What you gave up

You gave up Base ETH, which was paying fees on an L2. You did not receive POL, WETH, or USDC. If the point of holding ETH was to keep using Base, this route works against that. If the point was a Polygon venue that settles in Tether, the contract above is the one to match.

The fee coin changes ticker

Base takes ETH. Polygon takes POL. People still say MATIC out of habit. The symbol in the wallet should be POL, and the native balance is not an ERC-20 you approve. How cross-chain bridges work is why Basescan and Polygonscan never share one hash. There is no promised wait beyond that explanation.

Refuse the quote for these mismatches

Refuse it if the written asset is Circle USDC, native or bridged. Refuse it if the written asset is WETH. Refuse it if you needed ETH on Ethereum, chain 1, where blocks are about 12 seconds. Refuse it if the minimum USDT, after the ETH price, is a worse trade than you will take.

Legal

Risk disclosure

XAUConnect is a non-custodial swap aggregator. Digital assets are volatile and may lose value rapidly. Content on this page is educational and not investment advice. Verify every contract address on the official block explorer before approving a transaction.

Frequently asked questions

What is the best way to swap ETH from Base to USDT on Polygon?

The input is Base ETH, chain 8453, placeholder 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE, visible on Basescan as the account balance. Leave a fee remainder.

Is Polygon USDT the Ethereum Tether contract?

No. Ethereum Tether is 0xdAC17F958D2ee523a2206206994597C13D831ec7 on Etherscan. This route delivers 0xc2132D05D31c914a87C6611C10748AEb04B58e8F on Polygonscan, chain 137. Both are Tether and both use 6 decimals. A payment pointed at the Ethereum address will not spend the Polygon balance. Open Polygonscan on chain 137 and match the contract before you send.

Will I have POL because I sold ETH?

No. You sold ETH on Base and bought USDT on Polygon. POL is a separate native coin, marked 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE only while the wallet is on chain 137. USDT cannot pay fees. Bring POL before you try to transfer the Tether you just received. ETH sold on Base does not become that fee coin.

Does native ETH on Base need an allowance?

No. The gas coin is sent, not approved. You must leave enough ETH on chain 8453 to pay the fee or the swap never broadcasts. WETH at 0x4200000000000000000000000000000000000006 is a different input and a different page. This quote will not pull that wrapper. Check Basescan if you are unsure which ETH balance you hold.

Live execution

Trade on XAUConnect

Open the swap page with this cross-chain route pre-selected, then connect your wallet on the source chain to quote and execute. You keep the keys.

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