What does the checker verify on a container number validation?

Container check digits against ISO 6346, weight and unit consistency, date coherence, Incoterm and port-code sanity, required-field presence and more — 24 checks in total, each reported with the field it applies to.

Is my document stored?

No. The file stays in memory while it is processed and is never written to disk. The result is deleted automatically within 24 hours, and documents are never used to train models.

How much does it cost?

The first 3 documents every month are free. Paid plans start at $19 per month for 50 documents. A one-off Batch Pack covers 5,000 documents.

Container and Seal Number Validation

BOLCheck: Container and seal number validation. Free to try on a Bill of Lading, no signup required. Runs on Bill of Lading documents only, with results deleted within 24 hours.

A container number carries its own error detection: the last of its eleven characters is a check digit computed from the first ten. Recomputing it catches a mistyped or transposed character before the number reaches a booking, a manifest or a bank.

Try it: Container and Seal Number Validation

Paste the text of a Bill of Lading, or upload the PDF or a scan. Three documents a month are free and no account is needed.

What the eleven characters mean

· Characters 1 to 3: the owner code, registered with the Bureau International des Containers
· Character 4: the equipment category — U for a freight container, J for detachable equipment, Z for a trailer or chassis
· Characters 5 to 10: the six-digit serial number
· Character 11: the check digit

How the check digit is computed

Each of the first ten characters is mapped to a number — digits to themselves, letters through a table that skips every multiple of eleven — then multiplied by a weight of two raised to its position, running from one up to five hundred and twelve. The weighted values are added, the total is divided by eleven, and the remainder is the check digit, with a remainder of ten written as zero.

What a valid check digit does not prove

It proves the number is internally consistent. It does not prove the container exists, that the owner code is still registered, or that a particular line is moving it. Those need a lookup against the carrier or against the BIC register.

What gets checked

33 Bill of Lading fields are looked for, and 24 rules run over them. Every finding names the field it applies to, so it can be fixed in the source document.

· B/L No. (required)
· Booking No.
· B/L Type
· Place of Issue
· Date of Issue (required)
· Shipped on Board
· No. of Original B/L
· Carrier
· Shipper (required)
· Consignee (required)
· Notify Party
· Delivery Agent
· Place of Receipt
· Port of Loading (required)
· Port of Discharge (required)
· Place of Delivery
· Vessel (required)
· Voyage No.
· Marks & Numbers
· No. of Packages (required)
· Package Unit
· Description of Goods (required)
· Gross Weight (required)
· Net Weight
· Measurement
· HS Code
· Container Count
· Container Type
· Freight Terms
· Incoterms
· Declared Value
· Currency
· Place of Payment

Questions

What does the checker verify on a container number validation?: Container check digits against ISO 6346, weight and unit consistency, date coherence, Incoterm and port-code sanity, required-field presence and more — 24 checks in total, each reported with the field it applies to.
Is my document stored?: No. The file stays in memory while it is processed and is never written to disk. The result is deleted automatically within 24 hours, and documents are never used to train models.
How much does it cost?: The first 3 documents every month are free. Paid plans start at $19 per month for 50 documents. A one-off Batch Pack covers 5,000 documents.