A general purpose library for building credit card forms, validating inputs and formatting numbers.


A general purpose library for building credit card forms, validating inputs and formatting numbers.

For example, you can make an input act like a credit card field (with number formatting and length restriction):


Then, when the payment form is submitted, you can validate the card number on the client-side:

var valid = $.payment.validateCardNumber($('input.cc-num').val());
if (!valid) {
  alert('Your card is not valid!');
  return false;

You can find a full demo here.

Supported card types are:

  • Visa
  • MasterCard
  • American Express
  • Diners Club
  • Discover
  • UnionPay
  • JCB
  • Visa Electron
  • Maestro
  • Forbrugsforeningen
  • Dankort

(Additional card types are supported by extending the $.payment.cards array.)

Formats card numbers:

  • Includes a space between every 4 digits
  • Restricts input to numbers
  • Limits to 16 numbers
  • Supports American Express formatting
  • Adds a class of the card type (e.g. 'visa') to the input



Formats card expiry:

  • Includes a / between the month and year
  • Restricts input to numbers
  • Restricts length



Formats card CVC:

  • Restricts length to 4 numbers
  • Restricts input to numbers



General numeric input restriction.



Validates a card number:

  • Validates numbers
  • Validates Luhn algorithm
  • Validates length


$.payment.validateCardNumber('4242 4242 4242 4242'); //=> true 

Validates a card expiry:

  • Validates numbers
  • Validates in the future
  • Supports year shorthand


$.payment.validateCardExpiry('05', '20'); //=> true 
$.payment.validateCardExpiry('05', '2015'); //=> true 
$.payment.validateCardExpiry('05', '05'); //=> false 

Validates a card CVC:

  • Validates number
  • Validates length to 4


$.payment.validateCardCVC('123'); //=> true 
$.payment.validateCardCVC('123', 'amex'); //=> true 
$.payment.validateCardCVC('1234', 'amex'); //=> true 
$.payment.validateCardCVC('12344'); //=> false 

Returns a card type. Either:

  • visa
  • mastercard
  • amex
  • dinersclub
  • discover
  • unionpay
  • jcb
  • visaelectron
  • maestro
  • forbrugsforeningen
  • dankort

The function will return null if the card type can't be determined.


$.payment.cardType('4242 4242 4242 4242'); //=> 'visa' 

Parses a credit card expiry in the form of MM/YYYY, returning an object containing the month and year. Shorthand years, such as 13 are also supported (and converted into the longhand, e.g. 2013).

$.payment.cardExpiryVal('03 / 2025'); //=> {month: 3: year: 2025} 
$.payment.cardExpiryVal('05 / 04'); //=> {month: 5, year: 2004} 
$('input.cc-exp').payment('cardExpiryVal') //=> {month: 4, year: 2020} 

This function doesn't perform any validation of the month or year; use $.payment.validateCardExpiry(month, year) for that.

Array of objects that describe valid card types. Each object should contain the following fields:

  // Card type, as returned by $.payment.cardType. 
  type: 'mastercard',
  // Regex used to identify the card type. For the best experience, this should be 
  // the shortest pattern that can guarantee the card is of a particular type. 
  pattern: /^5[0-5]/,
  // Array of valid card number lengths. 
  length: [16],
  // Array of valid card CVC lengths. 
  cvcLength: [3],
  // Boolean indicating whether a valid card number should satisfy the Luhn check. 
  luhn: true,
  // Regex used to format the card number. Each match is joined with a space. 
  format: /(\d{1,4})/g

When identifying a card type, the array is traversed in order until the card number matches a pattern. For this reason, patterns with higher specificity should appear towards the beginning of the array.

Look in ./example/index.html

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We recommend you turn autocomplete on for credit card forms, except for the CVC field (which should never be stored). You can do this by setting the autocomplete attribute:

<form autocomplete="on">
  <input class="cc-number">
  <input class="cc-cvc" autocomplete="off">

You should also mark up your fields using the Autofill spec. These are respected by a number of browsers, including Chrome.

<input type="tel" class="cc-number" autocomplete="cc-number">

Set autocomplete to cc-number for credit card numbers and cc-exp for credit card expiry.

We recommend you to use <input type="tel"> which will cause the numeric keyboard to be displayed on mobile devices:

<input type="tel" class="cc-number">