ACE Entry Type 13 Mail Test: CBP Moves INT-057 and CBP-290 to Current

Key Points

• CBP deployed the Entry Type 13 (ET13) test in ACE on September 22, 2026, enabling formal mail-entry processing through the Automated Commercial Environment.
• Two implementation guides, INT-057 (U.S. Mail Processing) and CBP-290 (Mail Entry Type 13 Test), were moved from "Draft Chapters: Future Capabilities" to the current, deployed-functionality sections of CBP.gov on September 30, 2026.
• Brokers, software vendors, and importers filing or building integrations for U.S. mail entries should treat these guides as the authoritative technical specification, not earlier draft versions.
• No additional regulatory changes or duty-rate modifications were announced alongside this deployment; this is a filing-mechanics update.

On this page

1. What changed in ACE
2. The two promoted implementation guides: INT-057 and CBP-290
3. Who is affected
4. Required actions for filers and IT teams
5. Key references

CBP has officially moved the ACE implementation guides for Entry Type 13 mail processing from draft status to current status, reflecting the live deployment of ET13 functionality in ACE on September 22, 2026. Filers and system integrators should immediately replace any draft versions of INT-057 and CBP-290 with the current chapters now published on CBP.gov.

The links in this article go to the primary documents: the official CBP CSMS message itself. Read the source.

What changed in ACE

Entry Type 13 is the formal entry type designated for U.S. international mail shipments processed through CBP. Prior to the September 22, 2026 ACE deployment, ET13 functionality was in test or pre-deployment status, and the supporting technical guides were housed under the "Draft Chapters: Future Capabilities" section of CBP.gov, signaling that the specifications were subject to change.

With the deployment now live, CBP has promoted those draft chapters to the current, stable documentation sections. This promotion signals that the specifications are final for this phase of the test and that filers may rely on them for production filing.

The two promoted implementation guides: INT-057 and CBP-290

INT-057 (ACE Implementation Guide for U.S. Mail Processing) covers the integration requirements for how mail-processing data is transmitted into ACE. This is the guide most relevant to carriers, postal operators, and technology partners building or maintaining data pipelines into CBP systems for mail shipments.

CBP-290 (Mail Entry Type 13 Test) covers the entry-filing specifications for the ET13 entry type itself, including data elements, transaction sets, and expected system responses. Customs brokers and importers filing or sponsoring ET13 entries in ACE, as well as software developers building broker workstations or entry-management tools, should consult this guide for field-level requirements.

Both guides are now accessible in the Cargo Release section of the ACE deployment documentation on cbp.gov.

Who is affected

This update is relevant to any party that touches U.S. international mail entries in an ACE context:

• Customs brokers filing formal entries for imported mail shipments under ET13.
• Importers whose goods arrive via international mail and who may be required to file or participate in ET13 entries.
• Software vendors and ACE filers who maintain CATAIR-compliant messaging pipelines for mail processing.
• Trade-compliance managers who need to ensure their filing procedures and system configurations reflect current, not draft, specifications.

Parties who built systems or procedures against the earlier draft versions of INT-057 or CBP-290 should audit those configurations against the promoted current chapters to confirm alignment.

Required actions for filers and IT teams

• Download or bookmark the current versions of INT-057 and CBP-290 from the Cargo Release section of the ACE implementation guides on cbp.gov, and discard any saved copies of the draft chapters.
• If your organization developed ET13 filing logic or system integrations against the draft specifications, compare those specs against the now-current guides and correct any discrepancies before submitting production entries.
• Monitor CBP's Cargo Systems Messaging Service (CSMS) for any follow-on messages that may refine ET13 procedures as the test phase progresses.

Key references

• CSMS #70076746 (Sept 30, 2026): CBP announcement that INT-057 and CBP-290 have been moved from draft to current chapters in the ACE implementation guide library.
• CBP Cargo Systems Messaging Service (CSMS): Central repository for all ACE and trade-system operational messages.
• CBP.gov ACE Implementation Guides: Landing page for all current Cargo Release and other ACE implementation guides, including INT-057 and CBP-290.