Are sei1 addresses still valid after SIP-3?

The address format itself is still valid; you can still see balances at sei1 addresses on-chain. But Sei dApps and most new infrastructure are EVM-only and use 0x addresses. Without association, dApps treat your sei1 and 0x as two unrelated wallets.

Can I keep using a sei1 address forever?

You can hold SEI there, but you can't usefully spend it on EVM dApps without doing the association. New dApps deploy on EVM. Old CosmWasm dApps may have been deprecated or migrated.

Is the association reversible?

No. Once you associate sei1 with 0x, the on-chain record is permanent. There's no un-associate — but you can derive new addresses from the same seed phrase if you want a fresh start.

Do I lose my staking when I associate?

No. Staking on the Cosmos side stays staked. After association, Sei Wallet shows your stake under your unified identity. You can unstake, redelegate, or claim rewards normally.

What if I never used a sei1 address?

If you started using Sei after the EVM transition with a fresh 0x wallet, you don't need to do anything. Address association is only needed for users with existing sei1-side state.

Why didn't the chain auto-associate addresses derived from the same seed?

Different derivation paths (Cosmos vs Ethereum) produce different public keys from the same seed phrase. The chain can't know two addresses are the same person without an on-chain signal — which is what address association provides.

Migration · Cosmos sei1 → EVM 0x · SIP-3 in progress, completion target mid-2026

Migrate Cosmos Sei (sei1) to EVM (0x)

Sei is transitioning to EVM-only through 2026 (SIP-3, completion target mid-2026). If your SEI is at a Cosmos legacy address starting with sei1..., you can still see the balance, but Sei dApps now run on EVM and expect a 0x... address. You need to associate the two addresses to keep using Sei.

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Why this matters

Before SIP-3, Sei was a Cosmos SDK chain. Wallets generated sei1 addresses (a bech32 format common to Cosmos). Tokens lived at sei1 addresses. Smart contracts (CosmWasm) ran with sei1 calls.

As SIP-3 progresses, Sei is an EVM. Wallets generate 0x addresses (20-byte hex format common to Ethereum). Tokens live at 0x addresses. Smart contracts (Solidity) run with 0x calls.

The same seed phrase derives BOTH a sei1 address (Cosmos derivation path) and a 0x address (Ethereum derivation path). They're different addresses pointing at different on-chain states — until you tell the chain they belong to the same person. That's what address association does. It writes a record on-chain linking your sei1 and 0x addresses, so dApps and explorers can treat them as the same entity. See /learn/sei-addresses for the deeper explainer.

When you need to associate

You need address association if:

You held SEI at a sei1 address before the SIP-3 transition and want to keep using Sei dApps now (which expect 0x)
You used Cosmos-side staking and now want EVM-side dApp access
You held tokens deployed as CosmWasm contracts (e.g., USDC.n) that need conversion or migration

You don't need address association if:

You started using Sei during or after the SIP-3 era with a fresh 0x wallet
You only ever held SEI at a 0x address
You don't plan to use any Cosmos-legacy state

Step-by-step in Sei Wallet

Step 1 — Identify both addresses

In Sei Wallet, open Settings → Addresses. You'll see your current 0x address (the EVM address derived from your seed phrase, default for new transactions) and a "Cosmos legacy" entry showing your sei1 address. Both are derived from the same seed.

Step 2 — Check legacy balances

Click "View on Sei explorer" next to the sei1 entry. You'll see the on-chain state at that legacy address. If the sei1 address is empty, you don't need to associate — your funds are already at the 0x address. Skip to Step 5.

Step 3 — Initiate address association

Settings → Address Association → Associate sei1 with 0x. Sei Wallet shows a transaction preview: action AssociateAddress, from your 0x address, Cosmos pubkey from your seed, gas estimate <0.001 SEI. You need a small amount of SEI at your 0x address to pay gas.

Step 4 — Confirm and sign

Review the transaction. Sign with your local password (or your Ledger if connected). Sei Wallet broadcasts the association. Confirmation typically takes 1-2 blocks (under a second on Sei). If you have no 0x SEI yet, use the "Move from sei1" helper to fund gas, then associate, then move the rest.

Step 5 — Verify on the explorer

Open seitrace.com (or seistream.app) and search for either your sei1 or 0x address. The address detail page should show both addresses linked, with the AssociateAddress transaction in the history.

What about USDC.n specifically?

USDC.n was the bridged version of USDC on the Cosmos side of Sei. After SIP-3, USDC.n needs to be converted to native USDC (the EVM-side, Circle-issued version). Sei Labs asked USDC.n holders to convert before late March 2026. If you still hold USDC.n, the conversion path goes through Circle's CCTP. Sei Wallet has this flow built in: Settings → Token Migration → USDC.n to USDC. Verify the current state at sei.io/blog or via Sei Foundation Discord.