Guide
Do You Need a Continuous Bond or a Single Transaction Bond to Import Machined Parts?
A continuous bond or a single transaction bond is the customs bond that U.S. Customs and Border Protection (CBP) requires to be on file before it releases imported merchandise: a single transaction bond covers one entry, while a continuous bond covers many entries over time. The short answer: if you will import in more than a few entries a year, a continuous bond is usually the better fit, and a single transaction bond suits a one-off project. The break-even is a count of shipments, which you can compute once your broker quotes both.
By Saola Manufacturing engineering team · Published · Updated
General information, not legal or customs advice. Bond rules and surety terms change; confirm with a licensed customs broker or surety before you act.
This guide is for a purchasing or finance manager at a U.S. company that is about to import custom machined parts directly and wants to understand what the bond is, which type to buy, and how bond size is judged. It deliberately gives no premium or dollar figures, since those come from the surety and depend on your history; it gives the logic for deciding and the questions to ask your broker.
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What does a customs bond actually cover?
A customs bond is a guarantee to CBP, backed by a surety company, that you will pay duties and charges and meet the other conditions of entry. It is not insurance for your goods and it does not pay your duties for you.
Under 19 CFR 142.4, merchandise is not released when the entry documentation is received unless a bond has been filed, and that bond is a single entry or continuous bond on CBP Form 301 that contains the conditions of section 113.62 (19 CFR 142.4).
Those conditions are broader than paying the duty. The importer, called the principal, agrees to pay estimated and later-assessed duties, taxes and charges, to complete the entry, to produce required documents, to redeliver merchandise on CBP's demand if it fails admission or marking rules, and to follow security filing and electronic filing rules. If the principal defaults, the regulation states liquidated damages, which for most defaults involving merchandise equal the value of the merchandise (19 CFR 113.62). The surety then answers to CBP, and the practical effect for you is that a bond is a financial commitment as well as a document.
Cargo insurance, which covers loss or damage to the goods in transit, is a separate product and is not provided by the bond. Duties themselves are paid by the importer as part of the entry process; the bond is what stands behind that payment and the rest of the conditions.
What is the difference between a single transaction bond and a continuous bond?
A single transaction bond is written for one shipment and is set against its value and nature, while a continuous bond covers multiple transactions and is set against the character of your merchandise and the duties you pay in a year.
The two bond types are described in the bond application rules, which treat them differently: a person engaged in a single customs transaction may be asked for an application stating the value and nature of the merchandise, and a continuous bond application describes the general character of the merchandise and the total duties and taxes accrued in the prior calendar year (19 CFR 113.11). The table lines up what that means in practice.
| Point | Single transaction bond | Continuous bond |
|---|---|---|
| What it covers | One entry | Multiple entries charged against the same bond |
| What the application states | Value and nature of the merchandise | General character of the merchandise and duties and taxes accrued in the prior calendar year |
| Fits when | One-off project, prototype or trial order | Recurring program with several entries a year |
| Administration | A new bond is arranged for each entry | One bond stays on file until it is terminated or lapses |
| What drives its amount | The shipment in front of the surety | Your history and expected annual duties, reviewed by CBP |
| Main risk | Extra work and cost repeated for every entry | Becoming too small after volume or duty rates rise, or lapsing while freight is in transit |
How many shipments make a continuous bond the better choice?
Count your expected entries for the year and compare the cost of one continuous bond with the cost of that many single transaction bonds. If the count is more than a few, the continuous bond normally wins, and a program of regular shipments is well past that point.
Ask your customs broker for two numbers: the charge for one single transaction bond, and the annual cost of a continuous bond of the size the surety expects you to need. Divide the second by the first. The result is the break-even number of entries; if you plan more entries than that, buy the continuous bond. This guide leaves out the numbers on purpose, since they depend on the surety and on your profile.
Your entry count is set by the shipping plan, not by the part count. A program of 10,000 to 20,000 parts a year might move in a few full containers or in more frequent partial loads, and the choice between the two changes the number of entries. If you consolidate into fewer, larger shipments to save freight handling, you may lower the bond count too; if you ship small and often to keep inventory thin, you raise it. Settle the shipping plan first and read the bond decision off it. Landed-cost effects of shipment size are in the landed cost guide.
Two other things tilt toward continuous. First, a continuous bond is arranged once, so entries do not wait on a new application each time. Second, a single transaction bond is bought one entry at a time, so a late or unexpected shipment, such as a replacement lot after a quality hold, needs its own bond at short notice.
How is the bond amount decided?
There is no fixed rule in the regulation beyond a minimum; CBP judges whether the amount is sufficient using a list of factors, and sureties set what they will write. Expect the amount to track your expected duties and your record.
Section 113.13 sets only a floor of $100 for any CBP bond and then lists the guidelines CBP uses to judge sufficiency: your record of paying duties on time, your record of complying with redelivery and other demands, the value and nature of the merchandise involved, the degree of CBP supervision, your record of honoring bond commitments, and any other information in the application (19 CFR 113.13). A first-time importer has no record, so the application and the surety's underwriting carry more weight; ask the broker what the surety wants to see.
CBP also reviews bonds. If it finds a bond inadequate, it notifies the principal and the surety in writing, and the principal has 15 days to correct the deficiency; if CBP believes a transaction secured by a continuous bond would put revenue at risk, it may immediately require additional security (19 CFR 113.13).
Sizing logic for planning is simple. Estimate your annual dutiable value, apply the duty rates for your tariff classification and country of origin, and add the other charges that enter on the entry. A bond sized on last year's lower rate can become too small when a rate rises, so re-run the estimate when tariff treatment changes. Duty effects for Vietnam-origin goods are covered on the tariffs and origin page.
What happens if a continuous bond ends while goods are on the water?
No new customs transactions can be charged against a terminated bond, and a new bond must be filed before further customs activity. A lapse during transit means freight arrives with nothing to release it against.
Under 19 CFR 113.27, the principal can terminate in writing, effective on the date requested if that date is at least 10 business days after CBP receives the request, and the surety can end its agreement to accept future obligations on 30 days' notice unless it shows a shorter period is reasonable. After termination, no new transactions may be charged against the bond, and a new bond on Form 301 must be filed.
The same regulation family says the surety and the principal remain liable on a terminated bond for obligations incurred before termination (19 CFR 113.3), so termination does not erase an open obligation.
The practical lesson is to put the bond's renewal and termination dates in the same calendar as your purchase orders, and to ask your broker to warn you before any change. Never let the bond lapse between booking a shipment and its arrival.
How should you decide, step by step?
Fix the shipping plan, count entries, get both quotes from a broker, and buy the continuous bond if the count is above break-even; use single transaction bonds for one-off or trial lots only.
Step one is the shipping plan: containers or partial loads, shipments per year, and where the first lot goes. Step two is the entry count for the first twelve months, with trial and replacement lots included. Step three is the two broker quotes and the break-even division. Step four is to ask the broker how the surety will size the continuous bond for a new importer and what it will review at renewal.
If you are still qualifying suppliers, a single transaction bond for the first trial lot costs little regret, and you can move to a continuous bond when the program is confirmed. If the first order is already the start of a program, go to the continuous bond from the beginning. For a supplier check before the first shipment, see the guide on vetting a CNC machining supplier in Vietnam.
Saola’s quotes state the production location, and therefore the country of origin, which your broker needs alongside the classification. You can send a drawing through the quote page; for the process behind the parts, see CNC turning and CNC milling.
Frequently asked
Can I skip the bond on a small shipment?
The regulation lets the port director waive the surety or cash requirement when the value of the merchandise the bond secures does not exceed $2,500 (19 CFR 142.4). A production shipment of machined parts will usually exceed that, so plan to have a bond.
Does the bond pay my duties?
No. You pay the duties yourself through the entry process. The bond is the guarantee that you will pay them and meet the other conditions in 19 CFR 113.62, and if you default the surety answers to CBP.
Can my customs broker handle the bond?
Brokers commonly arrange bonds through sureties, but the bond is the importer's obligation. Ask the broker who the principal is on the bond you are buying and who receives CBP notices.
What if my volume or duty rate rises after the bond is set?
CBP reviews bond sufficiency, and under section 113.13 it can require additional security if revenue is at risk. Tell your broker when volume or tariff treatment changes so the bond is resized before CBP asks.
Is an import security filing bond a different bond?
Security filing compliance is one of the conditions in 19 CFR 113.62, so it is covered by the same basic bond. Confirm with your broker that the bond you buy includes it.
Sources
- 19 CFR 142.4, Entry bond (release of merchandise), Code of Federal Regulations, accessed 2026
- 19 CFR 113.11, Bond application, Code of Federal Regulations, accessed 2026
- 19 CFR 113.13, Amount of bond, Code of Federal Regulations, last amended 2015, accessed 2026
- 19 CFR 113.62, Basic importation and entry bond conditions, Code of Federal Regulations, accessed 2026
- 19 CFR 113.27, Termination of bond, Code of Federal Regulations, accessed 2026