Key Customs and Import Terms Every Importer Should Know (Glossary)

Cross-border trade runs on a specialized vocabulary, and misreading a single term can mean a held shipment, a penalty, or unexpected duties. This glossary defines the customs and import terms that come up most often when you move cargo through a U.S. port of entry like San Diego / Otay Mesa, grouped so you can find the concept you need fast.

Each term gets a plain-language definition plus the practical consequence behind it. Where a rule carries a hard deadline, a fee formula, or a dollar threshold, we spell it out so you know what actually triggers cost or risk. Nothing here is legal advice, but everything is written to be the accurate, citable answer to “what does this word mean.”

Entry & Filing

“Entry” is the umbrella process of legally bringing goods into U.S. commerce, and most of the paperwork and deadlines that trip up new importers live in this stage. These are the filings and identifiers that get cargo declared, released, and finalized.

Two of these terms carry the sharpest deadlines. The ISF must be transmitted before your goods are even loaded overseas, and liquidation is the moment your duty bill becomes final. Knowing where you are in this sequence tells you what can still be corrected and what is locked in.

• Importer of Record (IOR): The party legally responsible for declaring the goods, paying duties, and ensuring the entry is accurate. Liability sits here even if a broker files on your behalf.
• Entry: The formal act of declaring imported goods to CBP for release into U.S. commerce, supported by an invoice, packing list, and classification.
• Formal vs Informal Entry: Shipments valued over $2,500 generally require a formal entry with a customs bond; lower-value shipments can often clear as an informal entry with less paperwork.
• ACE (Automated Commercial Environment): CBP’s electronic system of record where entries, ISF filings, and PGA data are submitted and processed. It is the single window for U.S. import and export filing.
• ISF (Importer Security Filing, 10+2): For ocean cargo, an advance data filing of 10 importer elements plus 2 carrier elements, due at least 24 hours before the goods are laden aboard the vessel at the foreign port. Late or inaccurate filings can draw penalties up to $5,000 per violation.
• HTS (Harmonized Tariff Schedule): The classification system that assigns every product a 10-digit code, which in turn sets the duty rate and any special requirements. Correct classification is the foundation of a correct entry.
• Entry Summary (CBP Form 7501): The document that reports the value, classification, and duties owed for a shipment. It is how CBP and the importer reconcile what is actually due.
• In-Bond: A procedure that lets goods move under bond from the port of arrival to another port before entry is filed, without paying duties at the first port. Common when cargo clears inland rather than at the border crossing.
• Liquidation: CBP’s final calculation and acceptance of the duties owed on an entry, which closes the transaction. It usually occurs within 314 days and starts the clock on protest rights.

Duties, Fees & Bonds

This group covers what an import actually costs beyond the price of the goods, and the financial guarantee CBP requires before it will release cargo. Duties are only part of the bill; several fees apply on top, and a bond is mandatory for most formal entries.

Two terms here are worth memorizing because they cut both ways. De minimis can eliminate duty entirely on low-value shipments, while drawback can refund duty you already paid. Both are legitimate ways to lower landed cost when the facts fit.

• Duty / Tariff: The tax assessed on imported goods, set by the HTS classification and the country of origin. It is the primary cost lever in most import decisions.
• Customs Bond: A financial guarantee that duties, taxes, and fees will be paid and regulations followed. A single entry bond covers one shipment; a continuous bond (activity code 1 for importers) covers all entries for 12 months, with a minimum of $50,000.
• MPF (Merchandise Processing Fee): A fee CBP charges to process an entry. For formal entries it is 0.3464% of the entered value, subject to a minimum and maximum that CBP adjusts each year; informal entries pay a lower set fee.
• HMF (Harbor Maintenance Fee): A fee of 0.125% of cargo value assessed on goods arriving by ocean vessel through U.S. ports. It does not apply to air or land border shipments.
• De Minimis (Section 321): A provision allowing goods with a fair retail value of $800 or less, imported by one person on one day, to enter free of duty and formal entry. It does not cover every product, and certain goods and countries are excluded.
• Drawback: A refund of up to 99% of duties, taxes, and certain fees paid on imported goods that are later exported or destroyed. It is an underused way to recover cost on re-exported or manufactured-then-exported product.
• Country of Origin: Where a good was made or last substantially transformed, which determines duty rate, trade-agreement eligibility, and marking requirements. It is a factual question, not just where the shipment was sent from.

Agencies & Programs

CBP is the gatekeeper at the border, but it enforces the rules of many other federal agencies. When a shipment is held, it is often because a Partner Government Agency requirement was not met, not because of duties.

If you import food, drugs, cosmetics, agricultural products, or regulated goods, the program terms below decide whether your cargo clears or sits. Building these requirements into your entry before arrival is what keeps freight moving at a busy crossing.

• CBP (U.S. Customs and Border Protection): The federal agency that controls the flow of goods and people across U.S. borders, assesses duties, and enforces import laws at ports like San Diego / Otay Mesa.
• PGA (Partner Government Agency): Any federal agency besides CBP whose rules apply to certain imports, such as the FDA, USDA, EPA, or FCC. Their data is filed through ACE alongside the entry.
• FDA (Food and Drug Administration): Regulates the import of food, drugs, medical devices, cosmetics, and related products. Affected shipments require a prior notice or entry review before release.
• FSVP (Foreign Supplier Verification Program): An FDA requirement that the U.S. importer of a food product verify its foreign supplier meets U.S. safety standards. The FSVP importer must be identified at the time of entry.
• USDA (U.S. Department of Agriculture): Oversees the import of plants, animals, meat, and agricultural goods to protect against pests and disease. Permits or inspections often apply.
• CTPAT (Customs Trade Partnership Against Terrorism): A voluntary supply-chain security program. Members that meet CBP’s security criteria can receive benefits like fewer inspections and faster processing.

Cross-Border (U.S. / Mexico)

Otay Mesa is one of the busiest commercial land crossings on the southern border, and cargo moving through it touches two customs systems. Goods leaving Mexico clear Mexican customs on export, then U.S. customs on import, each with its own documents and classifications.

These terms are the Mexican-side counterparts to the U.S. concepts above. Importers running IMMEX or maquiladora operations especially need to understand them, because a mismatch between the pedimento and the U.S. entry is a common cause of delay.

• Pedimento: The official Mexican customs declaration that documents an import or export and the duties or taxes involved. It is the core clearance document on the Mexican side, comparable in role to the U.S. entry summary.
• Fraccion Arancelaria: Mexico’s tariff classification code for a product, the equivalent of the U.S. HTS number. It sets Mexican duty treatment and must be consistent with how the same goods are classified for U.S. import.
• IMMEX / Maquiladora: A Mexican program that lets companies temporarily import raw materials and components for manufacturing or assembly, then export the finished goods, deferring or avoiding certain duties. It underpins much of the cross-border manufacturing at the border.
• Customs Broker (Agente Aduanal): A licensed professional authorized to file customs declarations on behalf of importers and exporters. A bilingual, dual-side broker at Otay Mesa can coordinate both the Mexican pedimento and the U.S. entry so the two match.