EasyPost experienced a major incident on September 20, 2026 affecting USPS, lasting 5h 23m. The incident has been resolved; the full update timeline is below.
Affected components
Update timeline
- investigating Sep 20, 2026, 04:55 PM UTC
We are aware of an issue affecting USPS services, where some requests may be returning errors. We have confirmed the problem and our team is actively investigating.
- identified Sep 20, 2026, 05:12 PM UTC
We have identified the cause of the elevated errors affecting USPS services. The issue is related to an ongoing USPS maintenance rollout, and we've communicated to them that we are seeing elevated errors. They are investigating to determine if they should rollback or extend the window.
- identified Sep 20, 2026, 05:44 PM UTC
The errors affecting USPS services are caused by an issue on USPS's side, which USPS is actively working to resolve. We are in active contact with them as they work to restore normal service. What you may experience: Requests to USPS services may fail or return errors until USPS resolves the issue. Other carriers and services are unaffected. A specific restoration time is not yet available from USPS. We will update as soon as we have one, and no later than our next scheduled update in 30 minutes.
- identified Sep 20, 2026, 06:41 PM UTC
We've deployed and verified a fix on our side that reduce the blast radius of this issue. Shipment and rate requests that include USPS Ship along side other carriers are now succeeding normally. USPS Ship service remain affected. USPS Ship is still returning invalid rate data, so requests that require USPS Ship may continue to fail until USPS Ship resolves the issue on their side. We remain in active contact with USPS Ship on the underlying problem. What you may experience: Non-USPS requests should be working normally. Requests that depend on USPS Ship may still fail. A specific restoration time from USPS Ship is not yet available. We'll provide our next update within 30 minutes, or sooner as the situation changes.
- identified Sep 20, 2026, 07:25 PM UTC
No change to report at this time. USPS Ship services are still affected. USPS has not yet resolved the invalid rate data on their side, so USPS Ship dependent requests continue to fail the majority of the time. We'll share our next update within 45 minutes, or sooner if anything changes.
- identified Sep 20, 2026, 08:15 PM UTC
USPS Ship services remain affected. USPS Ship requests continue to fail the majority of the time. USPS has confirmed they are actively working on a fix, but no estimated resolution time is available yet. Next update within 45 minutes, or sooner if anything changes.
- identified Sep 20, 2026, 08:59 PM UTC
USPS Ship requests continue to fail the majority of the time due to a USPS-side issue. USPS is testing a fix, but no ETA on resolution provided. Next update in 60 minutes, or sooner if anything changes.
- monitoring Sep 20, 2026, 09:49 PM UTC
USPS has begun deploying a fix and we are monitoring our systems closely for recovery of USPS Ship. Next update within the hour, or sooner as recovery is confirmed
- resolved Sep 20, 2026, 10:19 PM UTC
USPS Ship services have recovered. Rating and shipping requests are now completing successfully.