# SiteCheck Trade & Energy – UPU S10 Postal Tracking Number Validator

> SiteCheck Trade & Energy – UPU S10 Postal Tracking Number Validator is a paid API for AI agents from api.tradeenergy-api.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-29).

Validates and decodes an international postal tracking number in UPU S10 format, returning the check digit result, service type, origin country, and tracking links (without live scan history).

## Facts

- Endpoint: GET https://api.tradeenergy-api.workers.dev/api/logistics/postal-upn-tracking?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sitecheck-trade-energy-upu-s10-postal-tracking-number-validator-4513deb1
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_T79N0Fscw82vFJZ05_KrY

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability sitecheck-trade-energy-upu-s10-postal-tracking-number-validator-4513deb1
```

Example prompt: Can you validate the international postal tracking number RR123456785GB for me — tell me if the check digit is correct, what kind of mail service it is, which country it was sent from, and give me any tracking links?

## When to prefer this

Use this endpoint when you need to validate the format and check digit of a UPU S10 international postal tracking number, decode the service type (EMS, registered, parcel, insured), identify the origin country, or obtain tracking page links — without needing live delivery scan events. Prefer this over carrier-specific live tracking APIs when you only need format validation and routing information, or when the tracking number's carrier is unknown and you want to identify it from the prefix.

## Known failure modes

- Invalid or malformed S10 number format returns an error (wrong length, missing letters, bad structure)
- Unknown origin country code returns unrecognised country
- Check digit mismatch returns checkDigitValid: false with both computed and expected values
- Non-GET method or missing 'number' query parameter causes a 4xx error
- Extremely obscure origin country codes may not resolve to a named country

## How this service works

International postal tracking number check (UPU S10 format, e.g. RR123456785GB): validates the 8-digit serial with the S10 check digit, decodes the service type from the first letter (EMS, registered, parcel, insured...), names the origin postal country from the last two letters, and returns tracking links (origin post and multi-carrier trackers). It does not read the item's live scan history.

## Output

Returns a JSON object with: the original number, extracted 8-digit serial, computed and expected check digits, a boolean check digit validity flag, the decoded service type (e.g. 'registered letter', 'EMS', 'parcel'), the two-letter service indicator, origin country name and ISO code, a timestamp, the data source (UPU S10 standard), tracking links to the origin postal carrier and multi-carrier trackers, and a note that live scan history is only available on the postal carriers' own tracking pages.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "number"
     ],
     "properties": {
      "number": {
       "type": "string",
       "description": "S10 number: 2 letters, 9 digits, 2-letter country code, e.g. RR123456785GB"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "note": "Valid S10 number. Scan history is on the posts' tracking pages.",
  "number": "RR123456785GB",
  "serial": "12345678",
  "source": "UPU S10 standard",
  "service": "registered letter",
  "checkedAt": "2026-10-23T09:37:58.776Z",
  "checkDigit": 5,
  "originCountry": "United Kingdom",
  "trackingLinks": [
   "https://www.royalmail.com/track-your-item#/tracking-results/RR123456785GB",
   "https://parcelsapp.com/en/tracking/RR123456785GB"
  ],
  "checkDigitValid": true,
  "serviceIndicator": "RR",
  "originCountryCode": "GB",
  "expectedCheckDigit": 5
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/sitecheck-trade-energy-upu-s10-postal-tracking-number-validator-4513deb1/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.tradeenergy-api.workers.dev](https://www.zero.xyz/host/api.tradeenergy-api.workers.dev/llms.txt)