Ethereum "Fusaka" upgrade on December 3, 2025

Last updated: March 30, 2026

Ethereum’s “Fusaka” upgrade is targeted for December 3, 2025 at ~21:49:11 UTC (slot 13,164,544). Paxos will pause on‑chain ETH/ERC‑20 deposits and withdrawals starting ~1 hour before the upgrade and resume within an estimated 2–4 hours after we confirm network stability. Trading on Paxos is expected to remain available throughout.

 What's Changing

The Fusaka upgrade introduces fee and scalability improvements (e.g., increased data capacity for rollups, data availability sampling, and modern signature support). It’s a planned, non‑contentious upgrade that has been tested on public testnets.

Timing

  • Target: December 3, 2025 at ~21:49:11 UTC (slot 13,164,544).
  • Paxos plan: Pause ETH/ERC‑20 on‑chain deposits and withdrawals ~1 hour prior; resume within 2–4 hours after stability verification.
  • Other networks: No impact expected.

Impact:

  • No action required for custody/balances; all assets held with Paxos remain safe. The corresponding amount of ETH and ERC-20 assets will be reflected on the upgraded Ethereum chain
  • Trading: We do not expect trading interruptions on Paxos.
  • Transfers (for Transfers API customers):

On-chain transfer processing for other networks is not expected to experience any interruption.

What does Paxos recommend to do in order to prepare for the Fusaka upgrade?

  • Consider pausing ETH/ERC‑20 withdrawal initiation in your app during the maintenance window to reduce user price‑movement risk while transactions wait in PENDING.
  • Inform users that ETH/ERC‑20 deposits made during the window will be credited after Paxos resumes processing.

Where can I receive updates? 

We will communicate all updates before, during, and after the Fusaka upgrade through the Paxos status page found at status.paxos.com. To receive real-time updates, select “Subscribe to Updates” in the upper right-hand corner of the page.

We expect minimal disruption, but in the event that there are any issues that impact your ability to trade or use our services, you can file a support ticket via support.paxos.com