Sei (SEI) Mandates EVM Migration for Exchanges by June 15

Iris Coleman May 07, 2026 21:32

Sei protocol's SIP-03 requires exchanges and custodians to migrate SEI holdings to EVM addresses before Cosmos support ends on June 15, 2026.

Sei (SEI) Mandates EVM Migration for Exchanges by June 15

The Sei protocol (SEI) has announced that all exchanges and custodians must migrate SEI token holdings from native Cosmos addresses (sei1...) to EVM-compatible addresses (0x...) by June 15, 2026. The transition is part of Sei's shift to a unified EVM-only architecture, a move that will deprecate Cosmos, CosmWasm, and IBC-related functionality.

This change, outlined in Sei Improvement Proposal 03 (SIP-03), means that exchanges and custodians who currently treat Sei's native and EVM implementations as separate chains must consolidate them into a single integration. Failure to complete the migration by the deadline will render funds held in unassociated native addresses inaccessible.

Key Details for Integration Teams

Sei EVM is not a new chain but an enhanced interface for interacting with the same blockchain. Each sei1... address has a corresponding 0x... address derived from the same public key, and no funds need to be moved during the migration. However, exchanges must ensure that customers' EVM addresses are surfaced and properly associated to avoid disruptions once Cosmos support is discontinued.

The technical reference for the migration outlines four upgrade paths for transitioning customer holdings to EVM addresses. Integration teams can access the full details in Sei's Exchange and Custodian Upgrade documentation.

Implications After June 15, 2026

Once Cosmos support is officially deprecated, several key functionalities will cease:

Funds linked to unassociated native addresses will become inaccessible.
Cosmos-native transaction interfaces, including RPC endpoints, will no longer function.
New address associations cannot be created using Cosmos wallets.

Exchanges and custodians that fail to complete the migration risk disrupting user access to SEI tokens and may face operational challenges as Cosmos-based infrastructure becomes obsolete.

Support and Next Steps

Sei Labs is offering dedicated support for integration teams navigating the migration process. Technical assistance is available through the Sei Tech Chat on Telegram and the Sei Discord server.

With just over a year until the June 15, 2026, deadline, exchanges and custodians must act swiftly to ensure a seamless transition. The success of this migration will likely set a precedent for other protocols considering similar architectural changes.

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