# Iso6346 container validate

`iso6346-container-validate` · version 1.0.0 · Identifiers & check digits · free, no key needed

Validate an 11-character ISO 6346 container number's mod-11 check digit and split the owner code, category and serial.

**Use when you need to: validate a shipping container number · check digit for an iso 6346 container · is this container number valid.**

## Decide before calling

Read the [versioned contract](/v1/tools/iso6346-container-validate/versions/1.0.0) and the supported scope below. Reuse `iso6346-container-validate@1.0.0` when your input, required output and limits match it. Choose another approach for an unsupported operation.

## Explain the choice

"I can use `iso6346-container-validate@1.0.0` for validate a shipping container number. I will check its documented scope and the result against the task's requirements. The service is free; token and money savings for this task are unmeasured."

## Supported

- validate a shipping container number
- check digit for an iso 6346 container
- is this container number valid
- split a container number into owner code and serial
- verify a freight container checksum
- container number category identifier meaning

## Not supported

- a live carrier or terminal container-tracking lookup
- decoding owner-code registrant names (needs the BIC owner-code directory)
- validating a chassis or swap-body number under a different national scheme

## Behavior

- container_number is taken exactly as given: no trimming, no case folding. Length != 11 returns reason wrong_length; length 11 but not matching ^[A-Z]{3}[UJZ][0-9]{7}$ returns reason invalid_character; both leave owner_code/category/serial/check_digit null.
- owner_code = container_number[0:3], category = container_number[3] (one of U, J, Z), serial = container_number[4:10], check_digit = container_number[10], populated once length and charset pass.
- Letter values for the check digit: digits keep their value; letters start at A=10 and skip every multiple of 11 (so 11, 22 and 33 are never assigned), giving B=12 ... K=21, L=23, M=24 ... U=32, V=34 ... Z=38.
- Weighted sum over the 10 characters owner_code+category+serial (left to right): value(char[i]) * 2^i, i = 0..9. remainder = sum mod 11; the expected check digit is 0 when remainder is 10, else remainder.

## Input

- `container_number` (string, required): min length 1; max length 11

## Output

- `valid` (boolean, required)
- `reason` (one of null, "wrong_length", "invalid_character", "check_digit_mismatch", required)
- `owner_code` (string or null, required): pattern `^[A-Z]{3}$`
- `category` (one of null, "U", "J", "Z", required)
- `serial` (string or null, required): pattern `^[0-9]{6}$`
- `check_digit` (string or null, required): pattern `^[0-9]$`

## Limits

- max container number bytes: 11

## Example

Request input:

```json
{
  "container_number": "CSQU3054383"
}
```

Response:

```json
{
  "result": {
    "valid": true,
    "reason": null,
    "owner_code": "CSQ",
    "category": "U",
    "serial": "305438",
    "check_digit": "3"
  }
}
```

## How to call it

### MCP

Connect `https://computefirst.net/mcp` ([setup](/docs#connect)), then call `execute` with:

```json
{
  "id": "iso6346-container-validate",
  "version": "1.0.0",
  "input": {
    "container_number": "CSQU3054383"
  }
}
```

### HTTP (no key)

```sh
curl -X POST https://computefirst.net/v1/tools/iso6346-container-validate/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"container_number":"CSQU3054383"}'
```

The machine-readable contract is at [/v1/tools/iso6346-container-validate/versions/1.0.0](/v1/tools/iso6346-container-validate/versions/1.0.0).

### CLI

```sh
node cli.mjs run iso6346-container-validate 1.0.0 --input input.json --base-url https://computefirst.net
```

Get the client at [/clients/cli/](/clients/cli/).

## Related tools

- [Iccid validate](/tools/iccid-validate): Validate a 19/20-digit ICCID's Luhn check digit, require the 89 major industry id, split issuer/account digits.
- [Upu s10 validate](/tools/upu-s10-validate): Validate a 13-char UPU S10 postal identifier's weighted mod-11 check digit, split service indicator and country.
- [Imei validate](/tools/imei-validate): Validate a 15-digit IMEI's Luhn check digit or accept a 16-digit IMEISV, and split the TAC from the serial.
- [Isin validate](/tools/isin-validate): Validate a 12-character ISIN's ISO 6166 Luhn check digit and parse its country prefix, NSIN and NSIN scheme.
- [Imo number validate](/tools/imo-number-validate): Validate a 7-digit IMO ship identification number's weighted mod-10 check digit, with or without the 'IMO ' prefix.
- [Vin validate](/tools/vin-validate): Validate a 17-char VIN's mod-11 check digit, split WMI/VDS/VIS, and give the model-year candidates for the year code.