Every ocean shipment entering the United States generates a bill of lading filing with U.S. Customs and Border Protection. These records contain the importer, the overseas supplier, the product description, the weight, and the ports of origin and destination. For sourcing and strategy teams, this public data is the most direct window into how competitors actually build their products.
Unlike trade show listings or supplier directories, bill of lading records show verified movement. A supplier that appears in these records has physically shipped goods across a border. That distinction separates real manufacturers from marketing entities.
Here is how to use this data to map a competitor’s supply chain.
1. Identify a Competitor’s Full Supplier Roster
The data point: ImportYeti holds U.S. bill of lading records from January 2015 onward, obtained through a Freedom of Information request to U.S. Customs . Searching a company’s legal name returns every overseas supplier that shipped goods to them, ranked by shipment volume.
Practical application: Pull the supplier list for two or three companies in your category. Look for suppliers that appear across multiple competitors. A factory shipping to three different U.S. brands is not a trader—it is a manufacturer with verified, recurring export volume.
Action step: Sign up for ImportYeti (free, but login is required after 25 page views) . Search each competitor’s legal name. Export the supplier list and flag any factory that ships to two or more importers in your product category. These are your highest-priority intelligence targets.
2. Quantify Dependency Through Shipment Frequency
The data point: Bill of lading records include shipment count, weight, and TEU (twenty-foot equivalent unit) for each supplier within a rolling 12-month window. PIERS, a commercial trade data provider, processed over 16 million bills of lading in 2023 covering 100% of U.S. port locations .
Practical application: A competitor with 150 shipments per year from a single supplier operates at a fundamentally different scale and risk profile than one with 15. The shipment count tells you how much of that competitor’s inventory depends on that factory.
Action step: For each competitor, identify their top three suppliers by shipment count. Calculate what percentage of total shipments each supplier represents. A supplier accounting for more than 60% of a competitor’s volume is a single point of failure—and a potential opportunity for you to offer that factory an alternative buyer.
3. Track Supplier Switching to Detect Strategic Shifts
The data point: Bill of lading data is time-stamped. By comparing a competitor’s supplier list in 2022 against 2024, you can see when they added a new factory, reduced volume with an existing one, or exited a country entirely.
Practical application: Supplier changes signal strategic decisions: cost pressure, tariff mitigation, quality problems, or capacity constraints. A competitor that shifted 40% of volume from China to Vietnam between 2023 and 2024 is responding to something specific.
Action step: Use ImportGenius or a similar bill of lading database to pull a competitor’s shipment history by month . Build a simple timeline showing when each new supplier appeared and when existing supplier volumes declined. Map those changes against known events—tariff announcements, quality recalls, port disruptions—to understand the trigger.
4. Map Your Competitor’s Port-to-Port Logistics Network
The data point: Bill of lading records include the foreign port of lading and the U.S. port of unlading. A competitor importing consistently through Shanghai to Los Angeles is using a different logistics strategy than one shipping from Ho Chi Minh City to Savannah .
Practical application: Port choices reveal inventory strategy. West Coast routing suggests speed-to-market for e-commerce or seasonal goods. East Coast routing suggests lower cost, longer lead times, and possibly distribution centers in the eastern U.S. The pattern shows how your competitor balances speed against cost.
Action step: For your top three competitors, list their primary port pairs and the carrier SCAC codes used. Note any recent lane shifts. If a competitor moved from Long Beach to Savannah in the last 18 months, they are likely repositioning inventory closer to eastern distribution centers—a signal of where their growth market is.
5. Use HS Codes to Size the Category and Spot Gaps
The data point: Every bill of lading record includes a six-digit HS code that classifies the traded product . Aggregating these codes across competitors shows the volume flowing through each product category.
Practical application: A competitor importing 50,000 kilograms per month under HS 9403 (furniture) has a different inventory position than one importing 5,000 kilograms. More importantly, comparing your own sourcing volume against theirs tells you whether you are competing at the same scale.
Action step: Search ImportYeti by HS code rather than company name to find all U.S. importers in your category . Sort by total weight or shipment count. Identify importers with high volume but few suppliers—they may be locked into a single factory and receptive to alternatives. Also note any HS subcategories your competitors import that you do not. Those are either adjacent products or gaps in your own catalog.
Building Intelligence from Public Records
Bill of lading data does not require a subscription to commercial intelligence platforms. ImportYeti provides free access to U.S. customs records going back to 2015 . The limitation is that records can be made confidential upon request to CBP, and supplier contact details are often missing . But for mapping structure—who supplies whom, at what volume, through which ports—the data is sufficient.
Start with one competitor. Pull their supplier list, sort by shipment count, and map the top five factories. Then do the same for a second competitor. The overlap between their supplier networks shows you where the category’s real manufacturing capacity sits. That overlap is where your sourcing strategy begins.
