CATAIR Appendix B: Valid Codes Reference for ABI Filers

Key Points

• CATAIR Appendix B (Valid Codes) is the ACE ABI CATAIR appendix that lists the code values ABI transactions accept, such as entry types, modes of transport, units of measure, fee and tax class codes, and status and disposition codes.
• CBP revises CATAIR Appendix B alongside ACE deployments and announces changes through CSMS messages, so a value list saved months ago may no longer match production.
• The most common CATAIR Appendix B problems are hard-coded values from an old copy, transmitting a retired code, and confusing Appendix B with the PGA appendix or the ACE error dictionary.
• Check the current CATAIR Appendix B on cbp.gov before changing a filing, especially when a transmission rejects on an invalid code or a new program introduces a new entry type, fee class or qualifier.

On this page

1. At a glance
2. What is CATAIR Appendix B and where does it come from?
3. When do brokers and software vendors use CATAIR Appendix B?
4. How does CATAIR Appendix B change?
5. Common CATAIR Appendix B errors
6. How CATAIR Appendix B relates to other ACE transactions
7. Frequently asked questions
8. What importers and brokers should do
9. Key references

CATAIR Appendix B is the Valid Codes appendix of the ACE ABI CATAIR, the CBP technical publication that ABI filers and software vendors use to build electronic transmissions. It lists the code values that ABI transactions accept across entry types, modes of transport, units of measure, fee and tax class codes, status and disposition codes and other code tables. Brokers' filing teams and ABI software vendors consult it whenever a transaction is built, changed or rejected on an invalid code, from cargo release through entry summary.

This entry reflects the position as of November 2026. The links in this article go to the primary documents: the CBP CATAIR publication pages and official tariff schedule pages themselves. Read the source.

At a glance

• Full name: ACE ABI CATAIR Appendix B (Valid Codes)
• Who prepares or uses it: Prepared and revised by CBP; used by ABI software vendors, customs brokers' filing teams and importer self-filers
• When in the lifecycle: Throughout, whenever a coded data element is transmitted in an ABI transaction
• System or channel: Published on cbp.gov as part of the ACE ABI CATAIR; values are validated by ACE on ABI transmissions
• Governing authority: CBP, through the ACE ABI CATAIR and CSMS announcements
• Revision date: Varies with ACE deployments; confirm the current version on cbp.gov
• Related terms: ACE Cargo Release, disposition codes, 1C release, ACE reconciliation, ACE in-bond, MID code

What is CATAIR Appendix B and where does it come from?

CATAIR Appendix B is the code-value reference inside the ACE ABI CATAIR, and it holds the lists of valid values rather than the record layouts that carry them. The CATAIR chapters describe each transaction record by record and field by field. When a field is coded, the chapter tells you the field exists and how long it is; CATAIR Appendix B tells you which values ACE will accept in it.

CATAIR Appendix B complements the entry summary tables in the CATAIR, including the entry type codes, fee class codes and units of measure that drive how an entry summary is built and how fees are calculated. Units of measure reported on an entry line also need to agree with the unit shown for the classification in the Harmonized Tariff Schedule.

What CATAIR Appendix B is not

CATAIR Appendix B is not the PGA appendix, which covers partner government agency message set data. It is not the port code appendix, and it is not the ACE error dictionary, which explains reject conditions rather than listing valid values. Keeping these three separate prevents most lookup mistakes.

When do brokers and software vendors use CATAIR Appendix B?

Brokers and ABI software vendors open CATAIR Appendix B in two recurring situations: when a transmission rejects on an invalid code, and when a new program introduces a new code such as an entry type, fee class or qualifier. In both cases the rule is the same: check the current value list before changing the filing.

Rejects on an invalid code

When ACE rejects a transmission because a coded field holds an unacceptable value, the filer should compare the transmitted value against the current CATAIR Appendix B rather than guessing at a fix. The error message points to the problem; Appendix B shows the acceptable values.

New programs and new codes

When CBP introduces a program that needs a new value, vendors must add it to their software tables and brokers must know when to use it. For example, an entry flagged for ACE reconciliation (ACE Reconciliation, entry type 09, the program for later reconciling undeterminable value, classification, 9802 or FTA issues) depends on codes that the software must carry correctly.

Cargo release status messages

CATAIR Appendix B also covers status and disposition codes. Through ACE Cargo Release (the ACE transaction succeeding the paper CBP Form 3461), CBP returns disposition codes (ACE cargo release disposition codes describing whether cargo was released, held, required documents, faced PGA action or was canceled). The best known is the 1C release (disposition code 1C, meaning CBP has released the entry), which is not by itself a final determination of admissibility or duty and not PGA clearance.

How does CATAIR Appendix B change?

CBP revises CATAIR Appendix B with ACE deployments and announces the changes by CSMS message. Because revisions follow deployment cycles, there is no fixed calendar to plan against; filers should confirm the current version and its revision date directly on the CBP CATAIR page.

Software vendors typically carry the CATAIR Appendix B tables inside their applications, so a CBP change only reaches the broker's screen after the vendor updates. Brokers should ask their vendor how quickly table updates follow a CSMS announcement. Connectivity, testing and certification questions about a new code go to the filer's ABI client rep (ABI client representative, the CBP Office of Trade contact assigned to each ABI filer).

Common CATAIR Appendix B errors

Most CATAIR Appendix B problems come from treating a value list as permanent when CBP actually maintains it as a living table.

• Hard-coded values from an old appendix: internal tools, spreadsheets or macros built from an earlier copy keep sending values that ACE no longer accepts.
• Using a retired code: a value that once worked may be withdrawn in a deployment, causing rejects or incorrect processing.
• Confusing the appendices: looking up a PGA qualifier in CATAIR Appendix B, or treating the error dictionary as a list of valid values, sends the filer to the wrong source.

The cost is mostly operational: rejected transmissions, delayed release, rework on entry summaries and, where a fee class or entry type is wrong, follow-up corrections. CATAIR Appendix B does not specify penalty amounts; confirm consequences for a specific filing with CBP or your broker.

How CATAIR Appendix B relates to other ACE transactions

CATAIR Appendix B supplies coded values across ABI transactions, but several related ACE functions draw their data from other sources.

• ACE AD/CVD case management: the ACE function and public ADCVD Search publishing Commerce case numbers, company suffixes and rates. Case data keyed on entry lines comes from there, not from Appendix B.
• MID code: the Manufacturer Identification code identifying the manufacturer or shipper on each line is not chosen from a list. It follows MID construction, CBP's rule for deriving the code from the manufacturer's country code, name, address number and city.
• ACE in-bond: the electronic in-bond system for moving unentered merchandise under bond; see our ACE in-bond guide. Confirm which coded values an in-bond transaction uses in the current CATAIR.
• ACE truck eManifest: the electronic truck manifest highway carriers transmit before arrival at a land border port. It is a carrier filing, not the importer's entry; confirm its code references in the current CATAIR.

Frequently asked questions

Where do I find CATAIR Appendix B?

CATAIR Appendix B is published by CBP on cbp.gov as part of the ACE ABI CATAIR. Always download the current version rather than relying on a saved copy.

Does CATAIR Appendix B include PGA codes?

CATAIR Appendix B is not the PGA appendix. Partner government agency message set values are covered separately, so check the PGA appendix for those.

Is CATAIR Appendix B the same as the ACE error dictionary?

No. CATAIR Appendix B lists valid code values, while the error dictionary explains why a transmission was rejected. Use both together when resolving an invalid-code reject.

How do I learn about changes to CATAIR Appendix B?

CBP announces CATAIR Appendix B changes by CSMS message and revises the appendix with ACE deployments. Subscribe to CSMS and confirm the revision on cbp.gov.

What importers and brokers should do

• Replace hard-coded code lists in internal tools with a process that checks the current CATAIR Appendix B on cbp.gov.
• Monitor CSMS for ACE deployment notices and confirm with your ABI software vendor when updated code tables will be installed.
• When a transmission rejects on an invalid code, check the error dictionary for the cause and CATAIR Appendix B for the valid value before resubmitting.
• Route connectivity or certification questions about new codes to your ABI client rep.

Key references

• ACE ABI CATAIR on cbp.gov: CBP's publication page for the CATAIR chapters and appendices, including Appendix B (Valid Codes).
• CBP Automated Commercial Environment: CBP's ACE landing page for deployment information and trade guidance.
• Harmonized Tariff Schedule of the United States: the official tariff schedule, including reporting units of measure.