IATA Flight Number Validation in Node.js — Airline Lookup & Parsing

1. What is an IATA flight number?

An IATA flight number (also called a flight designator) is a code assigned to a scheduled airline service. It consists of a 2-character airline code followed by a 1- to 4-digit number and an optional single-letter suffix. These identifiers appear on boarding passes, airport departure boards, flight-tracking apps, and GDS booking systems.

Some well-known examples: AA100 (American Airlines), LH438 (Lufthansa), BA15 (British Airways), EK1 (Emirates).

2. Structure breakdown

An IATA flight number has three parts. Understanding this structure helps when parsing user input, validating API payloads, or building flight search interfaces.

Combined, a flight number like LH438B breaks down as: airline code LH (Lufthansa), flight number 438, suffix B.

3. Why flight number validation matters

4. The right solution: one API call

The IsValid IATA Flight API validates the flight number format, parses it into its component parts, and enriches it with airline metadata — airline name, country, ICAO callsign, and more — all from a single GET request.

Get your free API key at isvalid.dev — 100 calls per day, no credit card required.

Full parameter reference and response schema: IATA Flight Validation API docs →

5. Node.js code example

Using the @isvalid-dev/sdk package or the native fetch API (Node 18+).

// flightValidator.js
import { createClient } from '@isvalid-dev/sdk';

const iv = createClient({ apiKey: process.env.ISVALID_API_KEY });

// ── Example usage ────────────────────────────────────────────────────────────

const result = await iv.iata.flight('AA100');

console.log(result.valid);        // true
console.log(result.airlineCode);  // 'AA'
console.log(result.flightNumber); // 100
console.log(result.airlineName);  // 'American Airlines'
console.log(result.suffix);       // null

if (result.valid) {
  console.log(`Flight ${result.airlineCode}${result.flightNumber} — ${result.airlineName}`);
  // → Flight AA100 — American Airlines
}

// flightBatch.js — validate multiple flight numbers sequentially
async function validateFlights(flightList) {
  const results = [];

  for (const flight of flightList) {
    try {
      const data = await validateFlight(flight);
      results.push({ flight, ...data });
    } catch (err) {
      results.push({ flight, valid: false, error: err.message });
    }
  }

  return results;
}

// ── Example ──────────────────────────────────────────────────────────────────

const flights = ['AA100', 'LH438B', 'BA15', 'INVALID', '123'];
const results = await validateFlights(flights);

for (const r of results) {
  const status = r.valid ? '✓' : '✗';
  const airline = r.airlineName ?? 'unknown';
  console.log(`  ${status}  ${r.flight.padEnd(10)}  ${airline}`);
}

6. cURL example

American Airlines flight 100:

curl -H "Authorization: Bearer YOUR_API_KEY" \
  "https://api.isvalid.dev/v0/iata/flight?value=AA100"

Lufthansa flight with suffix:

curl -H "Authorization: Bearer YOUR_API_KEY" \
  "https://api.isvalid.dev/v0/iata/flight?value=LH438B"

Invalid format:

curl -H "Authorization: Bearer YOUR_API_KEY" \
  "https://api.isvalid.dev/v0/iata/flight?value=INVALID"

7. Understanding the response

Response for AA100 (American Airlines):

{
  "valid": true,
  "airlineCode": "AA",
  "flightNumber": 100,
  "suffix": null,
  "airlineName": "American Airlines",
  "countryCode": "US",
  "countryName": "United States",
  "callsign": "AMERICAN",
  "icao": "AAL"
}

Response for an invalid flight number:

{
  "valid": false
}

8. Edge cases to handle

// Both codeshare partners have valid flight numbers
const marketing = await iv.iata.flight('BA1525');
const operating = await iv.iata.flight('AA100');

console.log(marketing.valid);      // true
console.log(marketing.airlineName); // 'British Airways'
console.log(operating.airlineName); // 'American Airlines'

const result = await iv.iata.flight('LH438B');

console.log(result.airlineCode);  // 'LH'
console.log(result.flightNumber); // 438
console.log(result.suffix);       // 'B'
console.log(result.airlineName);  // 'Lufthansa'

const r1 = await iv.iata.flight('AA0100');
const r2 = await iv.iata.flight('AA100');

console.log(r1.flightNumber); // 100
console.log(r2.flightNumber); // 100

const r1 = await iv.iata.flight('aa100');
const r2 = await iv.iata.flight('AA100');

console.log(r1.airlineCode); // 'AA'
console.log(r2.airlineCode); // 'AA'