What Happens at US Customs When You Import a Personal Shipment From Mexico

When a package from Mexico crosses into the United States, it doesn't just arrive at your door. It enters a complex inspection and clearance system where government agencies verify its contents, assess taxes and duties, and confirm it's legally importable. Understanding what happens at this stage helps you prepare your shipment correctly—and avoid costly delays or confiscation.

For individuals and small business owners shipping personal items or goods from Mexico, the customs process can feel opaque. But knowing the key checkpoints and requirements reduces risk and makes international shipping less intimidating.

The Entry Point: Where Your Shipment Lands First

Your package doesn't arrive at a random location. It enters through one of the US Customs and Border Protection (CBP) designated ports of entry—either a mail facility, cargo hub, or border crossing, depending on the carrier and shipping method.

Common entry points for Mexico shipments include:

  • Laredo, Texas (busiest for ground and small parcel shipments)
  • El Paso, Texas
  • San Diego, California
  • Tucson, Arizona
  • US postal facilities (if using USPS)

The entry point matters because processing times, facility congestion, and available services vary. A shipment entering through an overwhelmed hub may face longer delays than one entering through a quieter port.

The Customs Declaration: Your First Barrier

Before your shipment even arrives at the US border, it must be accompanied by a customs declaration form—typically a CBP Form 3299 (Declaration of Unaccepted Articles) or equivalent customs invoice, depending on the shipping method.

This declaration includes:

  • Complete itemized list of contents
  • Declared value of each item
  • Total shipment value
  • Description, quantity, and weight of goods
  • Harmonized Tariff Code (HS Code) for each item

This is critical: An inaccurate or incomplete declaration is one of the most common reasons shipments face delays or holds. CBP officers compare your declaration against what's actually in the box. Misrepresented values, omitted items, or vague descriptions raise red flags and trigger additional inspection.

The Screening and Risk Assessment Phase

Once your shipment arrives at the port of entry, CBP staff perform an initial screening. They use automated systems to assess risk based on:

  • The declared value and contents
  • The sender and recipient information
  • The shipment's origin and route
  • Patterns in your shipping history
  • Whether items are on restricted or prohibited lists

Not every package gets physically opened. Low-risk, low-value shipments often pass through screening without detailed inspection. High-value items, electronics, textiles, alcohol, medications, or anything that triggers an alert will be flagged for deeper review.

Physical Inspection and Contents Verification

If your shipment is selected for inspection—and many are—CBP officers will open it and verify that the contents match your declaration.

During this step, they check for:

  • Accuracy of declared value: Does the condition and quality of the items match the stated price?
  • Prohibited or restricted items: Weapons, drugs, counterfeit goods, certain agricultural products, endangered species materials, or unsafe electronics
  • Duty classification: The correct HS code and tariff rate for each item
  • Safety and health concerns: Products that don't meet US standards (labeling, certifications, chemical composition)
  • Trademark or copyright violations: Counterfeit branded goods

If everything matches the declaration and no prohibited items are found, the shipment moves to duty calculation.

Duty and Tax Assessment

Here's where costs beyond shipping appear. Once CBP verifies your goods are legal to import, they calculate import duties and taxes based on:

  • The declared value of each item
  • The HS tariff code specific to that product category
  • Country of origin (Mexico receives favorable tariff treatment under USMCA, but rates vary by product)
  • Applicable GST or sales tax depending on destination state

Mexico-US trade under USMCA reduces tariffs on many goods, but not all. Textiles, certain agricultural products, and other items may still face meaningful duty rates—sometimes 15–25% of the item's value.

Common surprise: Many individual shippers aren't prepared for duty costs. A $100 item from Mexico might incur $15–25 in duties on top of shipping fees. These charges are typically collected at delivery or before clearance release.

The Hold or Release Decision

Once inspection is complete and duties are assessed, CBP makes a final decision: release or hold.

Release means:

  • All checks passed
  • Duties and taxes are assessed and owed
  • The shipment moves to final delivery

Hold means:

  • Additional documentation is needed
  • Something doesn't match or raises concerns
  • The item may be restricted and requires special permits
  • The shipment is flagged for additional agency review (FDA, USDA, EPA, etc.)

Holds can last days or weeks, depending on the reason.

When Things Go Wrong: Common Delays and Rejections

Understanding what triggers problems helps you avoid them:

Undervalued Declarations

If CBP believes your declared value is artificially low (a common tactic to reduce duties), they may:

  • Hold the shipment for investigation
  • Assess duties based on their own valuation
  • In serious cases, reject or seize the shipment

Prohibited Items

Certain products cannot be imported by individuals, including:

  • Electronics that don't meet FCC standards
  • Medications without proper licensing
  • Certain agricultural products
  • Anything containing restricted materials

Discovery of prohibited items results in confiscation—no refund.

Missing Documentation

If your shipment contains items requiring certificates of origin, safety certifications, or special permits and you haven't provided them, the shipment will be held indefinitely until they're submitted.

Vague Descriptions

Saying "used items" or "merchandise" instead of specific product names confuses classification and invites deeper inspection.

The Last-Mile Delivery Phase

Once CBP releases your shipment, it moves to the final carrier (USPS, UPS, FedEx, or a local courier) for last-mile delivery. The carrier collects any unpaid duties or taxes from you at delivery.

You'll receive notice of the duty amount owed, either in advance or upon delivery attempt.

How Long Does the Whole Process Take?

A straightforward personal shipment from Mexico typically clears customs in 3–7 business days. However:

  • Simple, low-value items: 1–3 days
  • Inspected shipments: 5–10 days
  • Items on hold: 2–4 weeks or longer
  • Holiday periods: Add 5–10 days

Duration depends on port congestion, inspection requirements, and whether additional documentation is needed.

Why Professional Handling Matters

Navigating US customs requires accuracy in declarations, understanding HS codes, knowing which items face restrictions, and managing the paperwork correctly. A single error—an incomplete declaration, a misrepresented value, or a missed requirement—can stall your shipment for weeks.

For individual shippers, this complexity is often overwhelming. Professional logistics providers like Open Americas handle the entire process: correct declaration preparation, duty calculation, coordination with CBP, and real-time tracking through clearance.

Frequently Asked Questions

Do I have to pay duties on personal items from Mexico?

It depends. Goods imported for personal use are subject to duty just like any other import. However, items valued under $800 (as of 2024) may qualify for duty exemption under the Personal Exemption rule, but this is limited to once per month and certain restrictions apply. Many items over $800, or certain product categories, will incur duties based on the HS code and USMCA tariff rate. Always declare the true value—undervaluation can trigger investigations.

What happens if I don't declare something in my package?

If CBP discovers undeclared items during inspection, it's considered a customs violation. Consequences range from assessment of duties retroactively, to seizure of the undeclared items, or in serious cases, fines. Intentional misrepresentation is considered fraud. Always provide a complete, accurate itemized declaration.

Can I import medications or supplements from Mexico?

Personal medications for your own use can sometimes enter the US, but this is heavily regulated. Prescription medications require a valid US prescription and FDA approval of the specific drug. Over-the-counter items and supplements are restricted if they're not FDA-approved or if they contain banned ingredients. Many Mexican supplements and medications are simply not permitted. Check FDA regulations before shipping.

Why was my shipment held at customs?

Common reasons include incomplete declarations, items that don't match descriptions, suspected undervaluation, prohibited items discovered during inspection, missing documentation (certificates, permits, safety certs), or routine secondary inspection due to port congestion. Contact the carrier or CBP for specific hold information. Professional logistics providers can investigate on your behalf and guide next steps.

Get Help Navigating Customs

US customs clearance involves multiple decision points where mistakes are costly. From proper valuation and classification to timely documentation, the details matter.

Get a Shipping Quote — Open Americas Logistics handles international shipments from Latin America to the US, including customs clearance, last-mile delivery, and real-time tracking, all in one place. Let us manage the complexity while you focus on your shipment's arrival.