When an envelope or package of yours crosses from Spain into the United States, there's one agency that decides whether it goes through smoothly or gets stuck: the CBP, U.S. Customs and Border Protection. For most personal shipments, US customs is invisible: the shipment goes through and arrives. But when there's a problem — a badly made declaration, contents that draw attention, missing details — the shipment gets held, and from Spain it's not always easy to understand what's going on. This guide explains, without jargon, how the CBP works for personal shipments, what difference there is between sending documents and sending packages, how to declare properly and in which cases customs holds a shipment. If you're going to send something to the United States from Barcelona, this saves you grief.
What the CBP is and what it does with your shipment
The CBP is the federal agency that controls everything entering the United States: people, goods and, yes, also the envelope you send your cousin in Florida or the box you send a client in Texas.
When your shipment reaches a US point of entry, the CBP does three things with it:
1. It identifies it. It reads the paperwork: what it is, where it comes from, who it's going to, how much it's worth.
2. It classifies it. It decides whether it's a low-value personal shipment, a shipment subject to duties or something requiring review.
3. It releases it or holds it. If everything is in order, it lets it continue to the recipient. If there are doubts, it sets it aside for inspection or requests additional information.
95% of the work of avoiding a hold is done before the shipment leaves Spain: with a correct declaration. The CBP isn't capricious; it reacts to what it sees on the paperwork.
Documents vs. packages: two different worlds
The most important difference you need to understand is this: sending documents is not the same as sending goods, and the CBP treats them very differently.
Personal document shipments
Letters, contracts, powers of attorney, certificates, transcripts, legal or academic paperwork. Documents with no commercial value are the simplest shipment for US customs purposes:
- They're not goods, so they generate no customs duties.
- They clear the CBP quickly.
- What matters is that they're declared properly as documents, with no commercial value.
This makes sending papers to the United States, in practice, a clean process. You have the complete guide on how to do it — including the apostille and translation when needed — in our article on how to send documents to the United States from Spain.
Package and goods shipments
Here everything changes. A package with objects — gifts, new clothing, electronics, samples, products — is goods in the CBP's eyes, even if to you it's "a gift for my sister." And goods may be subject to:
- Customs duties depending on the type of product.
- Taxes and processing fees.
- Restrictions if the product is in a controlled category.
The key concept many people don't know is de minimis.
The de minimis threshold: the rule that changes the most
The United States applies a threshold called de minimis: a value below which a personal shipment enters without paying customs duties. It's the reason why a great many low-value personal packages arrive with no customs cost at all.
But there are three things you need to be very clear about:
1. The de minimis threshold and rules have changed in recent years and are subject to policy review. What was valid two years ago may not be today. That's why we don't give a fixed figure in this guide: what we do is confirm the current situation for you when you ask for a quote.
2. De minimis applies to the declared value. If you under-declare to "sneak" the shipment through, you're committing a customs offence, and if the CBP detects it, the hold is the least of it: there are penalties.
3. Even if you don't pay duties, the declaration has to be correct. Low value doesn't mean "no paperwork."
The practical conclusion: the real value of the contents matters, and it's worth knowing before sending what situation your package is in. That's exactly what we clarify for you in the quote.
The declaration: what information the CBP needs
A well-made customs declaration is what separates a shipment that flows from one that gets stuck. The CBP needs to see, clearly:
| Detail | Why it matters |
| Description of the contents | "Gift" or "documents" on their own isn't enough; you have to describe what it really is |
| Value | It must be the real, honest value of the contents |
| Nature of the shipment | Gift, personal effects, documents, sample... |
| Sender and recipient | Complete, correct details, exact destination address |
| Country of origin | Spain, in this case |
Typical declaration mistakes that trigger holds:
- Vague descriptions. "Various," "things," "gift." The CBP wants to know what's inside.
- Unrealistic value. Declaring $5 for contents worth $200. It's the most frequent cause of serious problems.
- Incomplete recipient details. A half-finished address or a phone number that doesn't work prevents the CBP or the courier from getting in touch if they need something.
- Discrepancy between what's declared and what's there. If they open the package and it doesn't match the paperwork, bad news.
When the CBP holds your shipment
US customs sets a shipment aside basically in these scenarios:
1. Incomplete or confusing paperwork. A detail is missing, the description can't be understood, the value isn't clear. The CBP doesn't guess: it holds and asks for clarification.
2. Suspicion of undervaluation. If the declared value doesn't match the apparent contents, the shipment is stopped for verification.
3. Restricted or prohibited contents. There are categories of products with entry restrictions in the US (certain foods, products of animal or plant origin, items subject to control). If your package contains something like that, it's held.
4. Random inspection. Sometimes it's simply your turn. The CBP carries out sample checks. With the paperwork in order, a random inspection is resolved and the shipment continues.
5. Pending payment of duties. If the shipment generates duties or taxes, it isn't released until they're paid.
If your shipment gets held, the first thing is not to panic: many holds are resolved by providing information or paying what's due. We have a dedicated guide on what to do when a shipment is held at customs, with the specific steps.
How to avoid problems with the CBP: checklist
Before sending to the United States, go over:
- Is it a document or a package with objects? Declare it accordingly.
- Is the description of the contents specific and truthful?
- Is the declared value the real one?
- Are the recipient's details complete, with an exact address and a working phone number?
- Are the contents legal and not in a restricted category for entry into the US?
- Do you know what customs duties situation your shipment is in?
If you're unsure on any of these points, don't send blind: we'll clarify it for free on WhatsApp before the shipment leaves.
Frequently asked questions about US customs
Do documents sent to the United States pay customs?
No. Personal documents with no commercial value are not goods: they generate no customs duties and clear the CBP quickly. The only thing that matters is that they're declared correctly as documents with no commercial value.
How much can I send to the US without paying customs?
The United States has a de minimis threshold below which a personal shipment enters without duties, but that threshold and its rules have changed and remain under review. That's why we don't give a fixed figure: we confirm the current situation when you ask for a quote.
What happens if I declare a lower value so as not to pay?
It's a customs offence. If the CBP detects undervaluation, it doesn't just hold the shipment: there can be penalties. Always declare the real value; it's the best protection for your shipment to arrive.
Why has my package been held at US customs?
The most common causes are incomplete paperwork, suspicion of undervaluation, restricted contents, random inspection or customs duties pending payment. Many holds are resolved by providing information or paying what's due.
Does Acacia Cargo help me with the declaration for the CBP?
Yes. We prepare the shipment paperwork correctly, advise you on how to declare the contents and value, and explain what customs situation your shipment is in before you send it. A well-made declaration is the best guarantee that it arrives without holds.
Send to the United States with no customs surprises
US customs doesn't have to be an obstacle. For personal documents it's a clean process; for packages, what makes the difference is an honest, complete declaration made before sending.
At Acacia Cargo we're a local operator in Barcelona with a regular corridor to the United States. We prepare your shipment at Carrer de Pelai 9, 08001, advise you on the declaration for the CBP, hand-carry it to the airport with a same-day cut-off at 18:00 and give you door-to-door tracking. Honest timings: documents from Spain to the US in 2 to 4 business days.
The price: closed on WhatsApp within 2 hours, quoted by weight and destination.
Ask us for a quote for your shipment to the United States on our quote page or come to the office. We serve you in Spanish, English and Filipino, Monday to Friday from 9:00 to 20:00.
Direct WhatsApp: +34 626 78 54 28
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