The U.S. Patent and Trademark Office (USPTO) has announced that a new serial number system for trademark applications will be implemented starting July 18, 2026. This change applies to new applications filed under Section 1 (used-based) or Section 44 (treaty-based) of the Trademark Act.
Previously, the USPTO assigned serial numbers sequentially in ascending order and is currently utilizing the “99” series.
Key Changes Include:
- New trademark applications will be assigned an 8-digit serial number sequentially, beginning with “50”.
- The total number of digits and its functionality as a unique digital identifier will remain exactly the same as before.
Please note that application types that use a special designation series are excluded from this update. For example, subsequent designations and extensions of protection under the Madrid Protocol will continue to use serial numbers starting with “79”.
As this new numbering series begins, it is crucial to determine priority based on the exact filing date and time, rather than relying solely on the sequence of the serial numbers.
If you have any questions regarding this upcoming regulatory change or need legal assistance with filing a U.S. trademark application, please feel free to contact our office at any time.
Inquiry: info@acilawgroup.com
