What is the US customs clearance process for imports?

Importing products into the US is exciting — until your shipment gets stuck at the port and you have no idea why.

That's usually a customs problem. And for most importers, customs clearance is the part of importing that nobody explains clearly.

So let's fix that. Here's exactly how it works, what you need, and how to make sure your goods clear without a headache.

What Is US Customs Clearance?

US customs clearance is the official process of getting your imported goods approved to enter the United States. Every single shipment coming into the US — no matter how big or small, it has to go through customs clearance.

The process is managed by US Customs and Border Protection (CBP), a federal agency that checks what's coming into the country, makes sure it's legal, and collects any duties and taxes owed.

Think of it as the government's way of saying we know what's coming in, where it's from, and you've paid what you owe. Only then do your goods get released.

How Does the US Customs Clearance Process Work?

Here's exactly what happens from the moment your freight arrives at a US port to the moment it's released to you.

Step 1: Your Shipment Arrives at the Port of Entry

Your goods land at a US port — whether that's Los Angeles, New York, Miami, or anywhere else. This is where the customs process officially begins.

Step 2: You (or Your Broker) File an Entry

An "entry" is basically a formal notification to CBP that your goods have arrived. It includes details about what you're importing, where it's from, and its value. You have 15 calendar days to file after your shipment arrives.

Step 3: CBP Reviews Your Documents

CBP checks your paperwork to make sure everything is accurate and compliant. This is why getting your documents right matters — any mistakes here can cause delays.

Cargo Held in Customs? Here’s How to Fix It Fast

Step 4: Duties & Taxes Are Calculated

Based on your shipment's value, country of origin, and HTS code (more on that later), CBP calculates what you owe in duties and taxes. Only if you pay, your goods will be released.

Step 5: Your Goods Are Inspected or Released

Most shipments are released without a physical inspection. But CBP can flag any shipment for a closer look — which can add a few days to the process.

Step 6: Entry Summary Is Filed

Within 10 business days of your goods being released, a final entry summary must be filed confirming all the details of the import.

Learn more

What Documents Do You Need for Customs Clearance?

This is where a lot of small business owners get tripped up. Missing or incorrect documents is the #1 reason shipments get delayed at customs. Here's what you'll typically need:

Importer Security Filing (ISF)

• Also known as "10+2," ISF must be submitted to CBP at least 24 hours before your cargo is loaded onto the vessel at the foreign port. 
• It includes details about your supplier, manufacturer, and shipment contents. Miss this deadline and you're looking at a $5,000 penalty — no exceptions. 
• This is your responsibility as the importer, so don't assume someone else is handling it.

Automated Manifest System (AMS)

• Filed by your carrier (not you), but important to know about. It's an electronic submission of your shipment's manifest to CBP before the vessel departs. 
• CBP uses it to pre-screen cargo for security risks before it even reaches US shores.

Commercial Invoice

• The most important document you'll submit. It tells CBP what you're importing, how much you paid for it, and where it came from. 
• Make sure the value is accurate — undervaluing goods to reduce duties is a serious offense.

Bill of Lading (or Airway Bill)

• Your shipment's travel document. Issued by the carrier, it proves your goods were shipped and are on their way to the US.

Packing List

• A detailed breakdown of exactly what's in each box or container — quantities, weights, and dimensions. CBP uses this to verify your commercial invoice.

HTS Code

• Every product imported into the US is assigned a Harmonized Tariff Schedule (HTS) code. 
• This code determines how much duty you'll pay. Getting the wrong code can cost you money or flag your shipment for inspection.

Customs Bond

• If your shipment is valued over $2,500, you're required to have a customs bond. Think of it as a guarantee to CBP that you'll pay any duties owed. 
• You can get a single-entry bond (for one shipment) or a continuous bond (if you import regularly — much more cost effective).

Import License (if applicable)

• Some products — like food, firearms, or regulated goods — require a special import license. Check with CBP or your customs broker if you're unsure whether your product needs one.

⚠️ Disclaimer: The documents listed above are the standard requirements for most imports into the United States. However, the exact documents required can vary depending on the type of product, country of origin, mode of transport, and applicable regulations. Always consult with a licensed customs broker to confirm what's required for your specific shipment.

How Much Does US Customs Clearance Cost?

This is the question every importers asks — and the honest answer is: it depends. But let's break down exactly what you'll be paying for so there are no surprises when your freight arrives.

Import Duties

• This is the tax you pay to bring goods into the US. The amount depends on three things: what you're importing, where it's coming from, and your HTS code. So getting your HTS code right really matters.

Harbor Maintenance Fee (HMF)

• If your goods are coming in by ocean freight, you'll also pay a Harbor Maintenance Fee of 0.125% of your shipment's value. This goes toward maintaining US ports.

Customs Broker Fees

• If you're using a customs broker (which most importers should — more on that in the next section), expect to pay minimal chargers per shipment depending on complexity. Some brokers charge a flat fee, others charge by the service.

Port & Terminal Fees

• These are charged by the port or terminal where your goods arrive — things like container handling, and detention fees. These can add up quickly if your shipment gets delayed, so always aim to pick up your cargo on time.

💡 Pro Tip: Always ask your customs broker for a full cost breakdown before your shipment arrives. Knowing your landed cost upfront helps you price your products correctly and protect your margins.

Do You Need a Customs Broker?

Short answer — you don't legally have to use customs broker, but for most importers, it's absolutely worth it.

Here's why.

What Does a Customs Broker Do?

• A licensed customs broker handles the entire clearance process on your behalf. They file your entry, classify your HTS codes, calculate your duties, communicate with CBP, and make sure everything is submitted correctly and on time. 
• Think of them as your guide through the customs maze.

When You Should Use One

• You're importing for the first time
• Your products are complex or regulated (food, cosmetics, electronics, etc.)
• You're importing frequently and don't have time to manage it yourself
• You've had shipments delayed or flagged before
• You're unsure about your HTS classification

When You Might Be Okay Without One

• If you're importing low-value, straightforward goods and you're comfortable filing through CBP's ACE portal yourself, self-filing is an option. 
• But one mistake can cost you more than the broker's fee ever would.

Learn more

Common Mistakes That Cause Delays at Customs

Customs delays are frustrating — and most of them are completely avoidable. Here are the most common mistakes small business owners make and how to avoid them:

Wrong or Missing HTS Code

• This is the #1 mistake importers make. An incorrect HTS code means you could be overpaying on duties — or worse, underpaying and getting flagged by CBP. 
• Always verify your HTS code before your shipment ships, not after it arrives.

Late ISF Filing

• Remember — ISF must be filed at least 24 hours before your cargo is loaded at the foreign port. 
• Filing late or not at all can result in a $5,000 penalty and your shipment being held at the port. Don't leave this to the last minute.

Inaccurate Commercial Invoice

• If the value, description, or country of origin on your commercial invoice doesn't match what's actually in the shipment, CBP will flag it. 
• Make sure your supplier sends you an accurate invoice every single time.

Undervaluing Your Goods

• Some importers try to declare a lower value to reduce duties. 
• This is customs fraud and CBP takes it very seriously. The penalties far outweigh any savings — don't do it.

Missing or Incorrect Documents

• Forgetting to include your packing list, bill of lading, or any other required document will stop your shipment in its tracks. 
• Always do a document checklist before your freight departs.

Not Having a Customs Bond

• If your shipment is valued over $2,500 and you don't have a customs bond, your goods won't be released. Simple as that. 
• Make sure your bond is in place before your freight arrives.

Waiting Too Long to Pick Up Your Cargo

• Once your goods are released, the clock starts ticking. Leaving your container at the port too long means demurrage and detention fees that can pile up fast. 
• Have your logistics plan ready before your shipment clears.

⚠️ The bottom line: Most customs delays come down to paperwork errors and poor timing. Stay organized, work with a reliable broker, and always plan ahead.

Take Away?

Importing into the US doesn't have to be stressful. Once you understand the customs clearance process,  the documents, the costs, the steps,  it becomes just another part of running your business.

The key is to stay organized, get your paperwork right, and don't wait until your freight is already at the port to figure things out. Plan ahead, work with the right partners, and your shipments will clear smoothly every time.

And if you ever feel overwhelmed,  that's exactly what a good customs broker is for. We are here to make sure your freight clears without the headaches, so you can focus on what matters most: growing your business.

1. How long does US customs clearance take?

Most shipments clear customs within 1 to 3 business days if all documents are in order. However, if CBP flags your shipment for inspection or there are document errors, it can take longer. The best way to avoid delays is to get your paperwork right the first time.

2. What happens if my goods are held at customs?

CBP will issue a hold notice explaining why your shipment was stopped. It could be a document issue, a random inspection, or a compliance concern. You'll need to respond quickly — the longer your goods sit at the port, the more storage fees you rack up. Having a customs broker like Air7Seas in your corner means someone is already on it before you even know there's a problem.

3. What is an HTS code and how do I find mine?

An HTS (Harmonized Tariff Schedule) code is a 10-digit number that classifies your product for customs purposes. It determines your duty rate. You can look up codes on the official USITC website — but if you're unsure, ask your customs broker. Getting it wrong is an expensive mistake.

4. What is a customs bond and do I need one?

A customs bond is a financial guarantee to CBP that all duties and fees will be paid. If your shipment is valued over $2,500, it's required by law. You can choose a single-entry bond for a one-time shipment or a continuous bond if you import regularly — which is almost always the better value.

5. Do I need a customs broker?

You're not legally required to use one, but most small business owners find it's well worth it. A good broker handles everything — filing, classification, communication with CBP, and more. Air7Seas doesn't just clear your customs — they also offer freight forwarding, cargo insurance, and end-to-end logistics support, so you have one trusted partner for your entire supply chain.

6. What is the difference between ISF and AMS?

ISF (Importer Security Filing) is filed by you or your broker before your cargo is loaded overseas. AMS (Automated Manifest System) is filed by your carrier. Both are required for ocean shipments — and both need to be accurate and on time to avoid holds and penalties.

7. What costs should I budget for customs clearance?

Budget for import duties, Merchandise Processing Fee (MPF), Harbor Maintenance Fee (HMF if ocean), and your customs broker fees. The exact amount depends on your product, its value, and where it's coming from. Ask Air7Seas for a landed cost estimate before your shipment departs — no surprises, no guesswork.