Amazon.com has reached a new agreement with the U.S. Postal Service to continue handling a significant portion of its package deliveries, maintaining one of the largest logistics partnerships in the country.

According to sources cited by Reuters, the deal allows Amazon to retain roughly 80% of its existing delivery volume with USPS, amounting to more than 1 billion packages annually. Amazon remains the Postal Service’s largest single customer under the arrangement.

The agreement follows concerns that Amazon could shift more of its logistics operations in-house, a move that would have posed a major financial challenge for USPS. The Postal Service operates on an estimated $80 billion budget, with Amazon accounting for approximately $6 billion in annual revenue, according to individuals familiar with the business relationship.

Amazon said in a statement that the new deal strengthens its longstanding partnership with USPS and will allow both organizations to continue serving customers and communities.

Tensions had emerged in recent months after USPS explored plans to auction access to its last-mile delivery network. Amazon had criticized the proposal and reportedly warned it could reduce its reliance on the Postal Service by as much as two-thirds.

The new agreement appears to ease those concerns, ensuring continued collaboration between the two entities as both navigate rising delivery demand and evolving logistics strategies.

USPS did not immediately comment on the finalized terms of the deal.