Unexpected customs charges usually come from a mismatch between the seller's estimate and the information used for the U.S. import entry. Your final delivered cost may include the merchandise price, transportation, customs duty, applicable taxes, and separate carrier or broker fees.

The safest approach is to check four details before ordering: the product's country of origin, its tariff classification, the customs value, and who will pay for clearance.

U.S. scope: Rules depend on the destination country and product. This guide is for goods entering the United States. A low-value or gift rule from the United Kingdom, European Union, or another country shouldn't be applied to a U.S. shipment without checking that country's authority.

The 12 mistakes at a glance

1. Budgeting from the item price alone

A $200 purchase can cost more than $200 by the time it reaches your door. Add the shipping charge, any insurance, customs duty, applicable tax, brokerage or handling fees, and possible storage or return costs.

Use this planning equation:

Estimated landed cost = merchandise + transport + duty + applicable tax + carrier or broker charges

That is a budgeting formula, not a universal customs formula. The value used to calculate U.S. duty may not equal your complete checkout total. Don't automatically apply a cost-insurance-freight, or CIF, formula from another country.

If the seller collects an import-charge estimate at checkout, save the terms and order summary. Confirm whether the amount is prepaid, an estimate, or a separate charge that could be adjusted later.

2. Assuming a low-value shipment is automatically exempt

The familiar $800 threshold should not be treated as a permanent guarantee that a U.S.-bound parcel will have no duty, tax, or clearance charge. CBP's e-commerce FAQs state that the suspension described there applies to merchandise valued at $800 or less arriving by any mode unless a separate exception applies.

Check the rule when you order and again if the shipment is delayed. A change in the law, an exception for the product, or a different entry process can affect the result.

3. Confusing informal entry with duty-free treatment

CBP says goods valued below $2,500 that arrive by mail or freight may, in most cases, use an informal entry. That describes how the shipment is entered, not whether it is free of duty, taxes, or private carrier charges.

Don't use the $2,500 informal-entry figure as a substitute for checking the actual tariff treatment. A shipment can have a simpler entry process and still generate a bill.

4. Using the shipping location as the country of origin

The country where a package begins its final journey isn't always the country of origin. Goods made in China could be stored and shipped from a warehouse in another country. That difference can affect the duty rate and whether additional trade measures apply.

Ask the seller for the manufacturing country and make sure the commercial invoice uses the same information. A warehouse address, return address, and country of origin are not interchangeable.

5. Guessing the HS or HTSUS code

The Harmonized System, or HS, classification identifies the type of merchandise. U.S. entries use the more specific Harmonized Tariff Schedule of the United States, or HTSUS, classification.

Product names alone are often insufficient. Material, function, construction, components, and intended use can all matter. A sweater, electronic component, or piece of furniture may fall under different lines depending on its characteristics.

Don't copy a code from a similar online listing. Give the seller or customs broker a complete description and ask how the classification was selected. If the product is unusual or the rate difference is significant, request a professional review before shipment.

6. Using an old or generic tariff rate

Duty rates can depend on the product classification, country of origin, customs value, trade preferences, additional measures, and the date of entry. A calculator that uses the wrong country or an old rate can produce a precise-looking but inaccurate answer.

Treat online calculators as planning tools. Recheck the result against current U.S. tariff information or ask a licensed customs broker, especially for commercial quantities or products subject to special tariffs.

7. Understating the value or falsely marking a sale as a gift

A lower declared value may look attractive, but it creates a documentation problem if the invoice, payment record, and package label do not match. Don't ask a seller to split an order, falsify an invoice, or describe a purchase as a gift.

CBP's FAQ describes a bona fide gift as an item formerly owned by a donor and given outright without compensation or a promise of compensation. A commercial purchase doesn't become a gift because someone checks a box on a postal form.

Use truthful records for the transaction. If the item was genuinely given by an individual, describe the contents and circumstances accurately and keep any available evidence of the gift.

8. Treating CN22 or CN23 as a simple checkbox

For international mail, CBP says the seller should affix a completed CN22 or CN23 declaration to help move the package through examination. These forms support clearance; they don't create a blanket fee exemption.

Before dispatch, check that the declaration matches the order's:

• Product description
• Quantity and units
• Value and currency
• Country of origin
• Sender and recipient information

A courier may transmit customs data electronically instead of using a postal CN22 or CN23. Ask the seller or carrier which documents apply to the shipping method.

9. Using a vague description or incorrect quantity

Descriptions such as “parts,” “samples,” or “accessories” may not tell customs what the goods are. An incomplete description can lead to a request for more information, a classification problem, or a delay.

The invoice should identify the actual product and, where useful, its material, model, function, and quantity. The number of units and the total value should match the order confirmation and payment record.

Correcting a discrepancy before the parcel leaves the seller is usually easier than correcting an entry after arrival.

10. Ignoring permits and restricted-goods rules

Some products require additional review, certificates, permits, or agency declarations. Examples can include certain medicines, food, plants, animal products, batteries, chemicals, and regulated electronic equipment.

Customs duty is not an admission guarantee. Paying a bill won't make a prohibited product acceptable or replace a required permit. Check the product restrictions before ordering, and ask the seller whether the shipment includes the documents needed for the United States.

11. Failing to identify the broker and private carrier fees

The person collecting money from you may not be CBP. A courier, customs broker, postal operator, or delivery company can charge for brokerage, advancing payment, handling, or storage in addition to government-assessed duty.

CBP explains that courier shipments are usually expedited by a customs broker hired by the commercial service. International postal merchandise follows a different process after arriving in the United States. Ask these questions before buying:

1. Is duty prepaid or collected on delivery?
2. Who is making the customs entry?
3. Is a broker or advancement fee separate?
4. What happens if the package is held or returned?
5. Who pays storage or re-delivery charges?

CBP's FAQ also says an entry can be made by the owner or purchaser, or by a properly designated licensed customs broker. Keep the seller's written answer if the listing promises delivered-duty-paid shipping.

12. Paying twice or ignoring a customs hold

A marketplace may collect an import-charge deposit while a carrier later sends an invoice. Those amounts may relate to the same shipment, but you shouldn't assume they are either duplicates or separate charges.

Compare the tracking number, airway bill, order number, invoice date, and line-item descriptions. Ask the marketplace or carrier to explain any amount that appears twice before paying it.

If a package is held, don't ignore the notice. The carrier or broker may need an invoice, proof of payment, product details, an origin statement, or a permit. Use the carrier's official website or phone number rather than a payment link in an unexpected text message.

How to estimate U.S. import costs before ordering

Use a worksheet instead of relying on one headline percentage.

1. Confirm the destination. The U.S. state may affect sales or use tax, while the entry country determines customs treatment.
2. Record the complete order value. Include each product, quantity, discount, and currency.
3. Confirm the shipping method. Postal and courier clearance processes can differ.
4. Ask for the country of origin. Don't substitute the seller's warehouse location.
5. Identify the likely HTSUS classification. Use the product's material, function, and specifications.
6. Check the customs value and duty base. Don't assume the duty base is the same as the amount charged to your card.
7. Add applicable taxes and private fees separately. Look for brokerage, handling, advancement, storage, and return charges.
8. Confirm who pays. Save the checkout terms and any message promising that import charges are included.

Illustrative estimate

Suppose a product costs $200, transport costs $35, the assumed duty base is $200, the assumed duty rate is 5 percent, and the carrier charges $18 for clearance:

This example demonstrates how separate charges add up. It does not establish the correct rate or duty base for a real product. If the marketplace already collected the carrier charge, don't add it again.

Duty, tax, and brokerage charges are not the same

The United States doesn't use a single nationwide import VAT rate for ordinary consumer purchases. Don't copy a 20 percent VAT calculation from a European purchase and apply it to a U.S. delivery.

An invoice labeled “import charges” may combine several categories. Request an itemized explanation before deciding whether the amount is correct.

What to do when a package is held at customs

Follow this order:

1. Verify the notice. Enter the tracking number directly on the carrier's official site.
2. Find the specific problem. Ask whether the hold concerns missing documents, unpaid charges, an inspection, product restrictions, or incorrect recipient information.
3. Gather evidence. Have the order confirmation, invoice, payment record, product page, specifications, origin information, and any permit ready.
4. Send consistent documents. Don't submit a lower value or a new description simply to release the parcel.
5. Pay only through a verified channel. Request an itemized bill showing government charges separately from carrier fees.
6. Escalate to the right party. Contact the seller for a false description or a promise that duties were included; contact the carrier or broker for a clearance invoice; contact CBP or the broker for questions about the official entry or admissibility.
7. Ask about the response deadline. A hold can become more expensive if storage or return arrangements apply.

A seller can't necessarily change a government assessment after the package enters the country, but it may be able to correct inaccurate paperwork or address a promise made at checkout.

Frequently asked questions

Does a package under $800 automatically enter the United States without fees?

No. CBP's e-commerce FAQ describes a suspension applying to merchandise valued at $800 or less arriving by any mode unless an exception applies. Verify the rule and any exception before relying on the threshold.

Can I ask a seller to mark a purchase as a gift?

No. A commercial purchase should be declared as a purchase. CBP describes a bona fide gift as property formerly owned by a donor and given without compensation or a promise of compensation. A gift label isn't a way to avoid charges.

Does the buyer complete the CN22 or CN23?

For international mail, the seller or shipper generally prepares and attaches the completed postal declaration. Review the information if you receive a copy, and ask the carrier what applies to a courier shipment.

Who should I contact about an unexpected customs bill?

Start with the party that issued the bill. The carrier or broker handles its own service charges, the seller can address inaccurate paperwork or checkout promises, and CBP or the broker can explain questions about the import entry. Compare the bill with your order records before paying.

Official references

• CBP guidance on Internet Purchases
• CBP e-commerce frequently asked questions

Before placing the order, save the product page, checkout terms, promised delivery terms, and payment receipt in one folder. Those records are the quickest way to identify whether a later charge is a government assessment, a carrier fee, or a billing error.