Credit/Debit Card Number Validation Regular Expression

A valid credit or debit card number follows specific patterns defined by card issuers. This regex validates the format of major card types including Visa, Mastercard, American Express, Discover, Diners Club, and JCB based on their IIN (Issuer Identification Number) ranges and length requirements. Card numbers should be validated without spaces or dashes. Credit card numbers are a specialized type of number pattern.

Recommended Solution

^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|3[47][0-9]{13}|3(?:0[0-5]|[68][0-9])[0-9]{11}|6(?:011|5[0-9]{2})[0-9]{12}|(?:2131|1800|35\d{3})\d{11})$

Explanation

^ - Start of the string.
4[0-9]{12}(?:[0-9]{3})? - Visa: Starts with 4, followed by 12 or 15 more digits (13 or 16 total).
5[1-5][0-9]{14} - Mastercard: Starts with 51-55, followed by 14 more digits (16 total).
3[47][0-9]{13} - American Express: Starts with 34 or 37, followed by 13 more digits (15 total).
3(?:0[0-5]|[68][0-9])[0-9]{11} - Diners Club: Starts with 300-305, 36, or 38, followed by 11 more digits (14 total).
6(?:011|5[0-9]{2})[0-9]{12} - Discover: Starts with 6011 or 65, followed by 12 more digits (16 total).
(?:2131|1800|35\d{3})\d{11} - JCB: Starts with 2131, 1800, or 35, followed by appropriate digits (15-16 total).
$ - End of the string.

Notes

This regex validates the format and IIN ranges but does NOT perform Luhn algorithm validation.
For production use, implement the Luhn algorithm (checksum validation) in addition to format validation.
This regex expects card numbers without spaces, dashes, or other separators. Preprocess input to remove formatting.
Card number formats can change as issuers introduce new IIN ranges. Keep patterns updated.
Never log, store, or transmit card numbers in plain text. Follow PCI DSS compliance standards.

Implementation

const cardRegex = /^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|3[47][0-9]{13}|3(?:0[0-5]|[68][0-9])[0-9]{11}|6(?:011|5[0-9]{2})[0-9]{12}|(?:2131|1800|35\d{3})\d{11})$/;
const isValidCardNumber = (cardNumber) => cardRegex.test(cardNumber);

import re

def is_valid_card_number(card_number):
  cardRegex = r"^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|3[47][0-9]{13}|3(?:0[0-5]|[68][0-9])[0-9]{11}|6(?:011|5[0-9]{2})[0-9]{12}|(?:2131|1800|35\d{3})\d{11})$"
  return re.match(cardRegex, card_number) is not None

use regex::Regex;

fn is_valid_card_number(card_number: &str) -> bool {
  let cardRegex = Regex::new("^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|3[47][0-9]{13}|3(?:0[0-5]|[68][0-9])[0-9]{11}|6(?:011|5[0-9]{2})[0-9]{12}|(?:2131|1800|35\d{3})\d{11})$")
    .expect("Could not parse card validation regex");
  cardRegex.is_match(card_number)
}

package main

import (
  "fmt"
  "regexp"
)

func isValidCardNumber(cardNumber string) bool {
  cardRegex := "^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|3[47][0-9]{13}|3(?:0[0-5]|[68][0-9])[0-9]{11}|6(?:011|5[0-9]{2})[0-9]{12}|(?:2131|1800|35\d{3})\d{11})$"
  re := regexp.MustCompile(cardRegex)
  return re.MatchString(cardNumber)
}

import Foundation

func isValidCardNumber(_ cardNumber: String) -> Bool {
  let cardRegex = "^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|3[47][0-9]{13}|3(?:0[0-5]|[68][0-9])[0-9]{11}|6(?:011|5[0-9]{2})[0-9]{12}|(?:2131|1800|35\d{3})\d{11})$"
  return NSPredicate(format: "SELF MATCHES %@", cardRegex).evaluate(with: cardNumber)
}

using System;
using System.Text.RegularExpressions;

class Application {
  static bool IsValidCardNumber(string cardNumber) {
    string cardRegex = "^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|3[47][0-9]{13}|3(?:0[0-5]|[68][0-9])[0-9]{11}|6(?:011|5[0-9]{2})[0-9]{12}|(?:2131|1800|35\d{3})\d{11})$";
    return Regex.IsMatch(cardNumber, cardRegex);
  }
}

import java.util.regex.*;

public class Application {
  public static boolean isValidCardNumber(String cardNumber) {
    String cardRegex = "^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|3[47][0-9]{13}|3(?:0[0-5]|[68][0-9])[0-9]{11}|6(?:011|5[0-9]{2})[0-9]{12}|(?:2131|1800|35\d{3})\d{11})$";
    Pattern pattern = Pattern.compile(cardRegex);
    Matcher matcher = pattern.matcher(cardNumber);
    return matcher.matches();
  }
}

<?php
function isValidCardNumber($cardNumber) {
  $cardRegex = "^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|3[47][0-9]{13}|3(?:0[0-5]|[68][0-9])[0-9]{11}|6(?:011|5[0-9]{2})[0-9]{12}|(?:2131|1800|35\d{3})\d{11})$";
  return (bool) preg_match("/" . $cardRegex . "/", $cardNumber);
}
?>

Test Cases

Card Number	Type/Note	Valid
4532015112830366	Visa (16 digits)
4532015112830	Visa (13 digits)
5425233430109903	Mastercard
374245455400126	American Express
371449635398431	American Express
6011111111111117	Discover
6011000990139424	Discover
3056930902595100	Diners Club
36227206271667	Diners Club
3530111333300000	JCB
3566002020360505	JCB
123	Too short
4532-0151-1283-0366	Contains dashes
4532 0151 1283 0366	Contains spaces
1234567890123456	Invalid prefix
453201511283036	Invalid length for Visa
542523343010990	Invalid length for Mastercard
37424545540012	Invalid length for Amex
(empty string)	Empty string
abcd1234efgh5678	Contains letters