A general purpose library for building credit card forms, validating inputs and formatting numbers. Base on jquery.payment by @stripe, but without the jQuery.

Usage no npm install needed!

<script type="module">
  import payseraForkPayment from 'https://cdn.skypack.dev/@paysera/fork-payment';


Payment Build Status

A jQuery-free general purpose library for building credit card forms, validating inputs and formatting numbers. Heavily, heavily based on @stripe's jquery.payment library, but without the jQuery.

For example, you can make a 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.fns.validateCardNumber(document.querySelector('input.cc-num').value);

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
  • Discover
  • JCB
  • Diners Club
  • Maestro
  • Laser
  • UnionPay
  • Elo
  • Hipercard


Payment.formatCardNumber(element[, maxLength])

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
  • If second parameter is specified then card length will be limited to its value (19 digits cards are not in use despite being included in specifications)




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.fns.validateCardNumber('4242 4242 4242 4242'); //=> true

Payment.fns.validateCardExpiry(month, year), Payment.fns.validateCardExpiry('month / year')

Validates a card expiry:

  • Validates numbers
  • Validates in the future
  • Supports year shorthand
  • Supports formatted as formatCardExpiry input value


Payment.fns.validateCardExpiry('05', '20'); //=> true
Payment.fns.validateCardExpiry('05', '2015'); //=> true
Payment.fns.validateCardExpiry('05', '05'); //=> false
Payment.fns.validateCardExpiry('05 / 25'); //=> true
Payment.fns.validateCardExpiry('05 / 2015'); //=> false

Payment.fns.validateCardCVC(cvc, type)

Validates a card CVC:

  • Validates number
  • Validates length to 4


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


Returns a card type. Either:

  • visa
  • mastercard
  • discover
  • amex
  • jcb
  • dinersclub
  • maestro
  • laser
  • unionpay
  • elo
  • hipercard

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


Payment.fns.cardType('4242 4242 4242 4242'); //=> 'visa'

Payment.fns.cardExpiryVal(string) and Payment.cardExpiryVal(el)

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

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

Card Type functions

We've provided utility functions to change which card types can be identified by Payment.


Returns the array of card types.


Overrides the array of card types with a new array.


Add a new card type to the card array.


Remove a card type from the card array.


Look in ./example/index.html


Run npm run build

Running tests

Run npm run test

Autocomplete recommendations

We recommend you turn autocomplete on for credit card forms, except for the CVC field. 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="text" class="cc-number" pattern="\d*" autocompletetype="cc-number" placeholder="Card number" required>

Set autocompletetype to cc-number for credit card numbers, cc-exp for credit card expiry and cc-csc for the CVC (security code).

Mobile recommendations

We recommend you set the pattern attribute which will cause the numeric keyboard to be displayed on mobiles:

<input class="cc-number" pattern="\d*">

You may have to turn off HTML5 validation (using the novalidate form attribute) when using this pattern, as it won't match space formatting.