Solana Proposal Would Retire Durable Nonces and Require Recent Block Hashes
The proposed mainnet change could begin after May 5, 2027, giving users time to migrate.

Solana community members have proposed ending durable nonces and requiring each transaction to include a recent block hash, a change that would affect offline-signing and custody workflows.
The block hash requirement is intended to prevent replayed transactions. The proposal would also disable system-program instructions used to initialize, advance and upgrade nonce accounts.
Those instructions cover the lifecycle of nonce accounts, so applications that rely on them would need to change their transaction handling before the new requirements begin. Offline-signing and custody workflows may be affected.
Mainnet activation is proposed for after May 5, 2027, leaving a migration period before the change could take effect. That date is the earliest timing in the proposal, not a confirmed activation date.
Under the plan, transactions would use a recent block hash for replay protection, while the system-program instructions to initialize, advance and upgrade nonce accounts would be disabled. The proposal focuses on how transactions are signed, maintained and submitted across Solana’s network.