Base Mainnet Set for U16A Upgrade on October 8
- Base Mainnet U16A upgrade scheduled for October 8, temporary withdrawal pause.
- Ensure transactions are completed before U16A upgrade window.
- Base collaborates with J.P. Morgan for onchain financial innovations.

Base Mainnet, incubated by Coinbase, is set for the U16A Upgrade on October 8, 2025, temporarily halting withdrawals to Ethereum L1 from 1:00 to 3:00 UTC+8.
This upgrade’s importance lies in its synchronization with the Optimism Superchain initiative, indicating substantial institutional blockchain integration efforts, highlighting the need for timely withdrawal arrangements by users.
The Base Mainnet will undergo the U16A Upgrade on October 8, 2025, between 1:00 and 3:00 UTC+8. Users are advised to complete any pending withdrawals from Base to Ethereum L1 before the scheduled upgrade.
Base, a Layer 2 blockchain incubated by Coinbase, leads the upgrade as part of the Optimism Superchain initiative. Key figures like Jesse Pollak play significant roles in its development and governance.
Jesse Pollak, Lead, Base, stated, “We’ve achieved Stage 1 Decentralization, a critical milestone in building an open and global onchain economy…launching permissionless fault proofs and increasing the decentralization of our contract upgrade process with a security council.”
Immediate effects include temporary withdrawal disruptions from Base to Ethereum L1. During the upgrade, intra-Base transactions and deposits will proceed unaffected, ensuring ongoing user activities within L2 operations.
Financial institutions, such as J.P. Morgan, are exploring blockchain innovations on Base. This aligns with broader aims for onchain settlement and financial product development involving the blockchain industry.
Previous similar upgrades on Layer 2 platforms signal temporary withdrawal halts as routine protocol enhancements. Such experiences provide a benchmark for expected outcomes post-upgrade.
Financial outcomes may involve adjustments in Total Value Locked (TVL) and liquidity dynamics on Base. Historical trends from related upgrades support the expectation of enhanced integration and stability post-implementation.
J.P. Morgan is launching a USD-backed deposit token (JPMD) proof of concept on Base, a major milestone in bringing traditional banking institutions onchain, and shows how Base helps banks build trusted financial products.