SecureCreditCardFormatter

February 9, 2026 · View on GitHub

The SecureCreditCardFormatter formats and masks credit card numbers for secure display. It automatically detects card types, formats them appropriately, and masks sensitive portions.

Usage

Basic Usage

use Respect\StringFormatter\SecureCreditCardFormatter;

$formatter = new SecureCreditCardFormatter();

echo $formatter->format('4123456789012345');
// Outputs: "4123 **** **** 2345" (Visa)

echo $formatter->format('341234567890123');
// Outputs: "3412 ****** 90123" (Amex, 4-6-5 format)

echo $formatter->format('5112345678901234');
// Outputs: "5112 **** **** 1234" (MasterCard)

echo $formatter->format('36123456789012');
// Outputs: "3612 ****** 9012" (Diners Club, 4-6-4 format)

echo $formatter->format('4123456789012345678');
// Outputs: "4123 **** **** **** 678" (Visa 19-digit)

Custom Mask Character

use Respect\StringFormatter\SecureCreditCardFormatter;

$formatter = new SecureCreditCardFormatter('X');

echo $formatter->format('4123456789012345');
// Outputs: "4123 XXXX XXXX 2345"

Input Cleaning

The formatter automatically removes non-digit characters from the input:

use Respect\StringFormatter\SecureCreditCardFormatter;

$formatter = new SecureCreditCardFormatter();

echo $formatter->format('4123-4567-8901-2345');
// Outputs: "4123 **** **** 2345"

API

`SecureCreditCardFormatter::__construct`

__construct(string $maskChar = '*')

Creates a new secure credit card formatter instance.

Parameters:

$maskChar: Character to use for masking (default: '*')

`format`

format(string $input): string

Formats and masks the input credit card number.

Parameters:

$input: The credit card number (can include spaces, dashes, dots, etc.)

Returns: The formatted and masked credit card number

Masking

The formatter applies masking after formatting to ensure predictable positions:

Card Type	Example Input	Mask Range	Output
Visa (16)	`4123456789012345`	`6-9,11-14`	`4123 ** ** 2345`
Visa (19)	`4123456789012345678`	`6-9,11-14,16-19`	`4123 ** ** 678`
MasterCard	`5112345678901234`	`6-9,11-14`	`5112 ** ** 1234`
American Express	`341234567890123`	`6-11`	`3412 ****** 90123`
Discover	`6011000990139424`	`6-9,11-14`	`6011 ** ** 9424`
JCB	`3528000012345678`	`6-9,11-14`	`3528 ** ** 5678`
Diners Club (14)	`36123456789012`	`6-11`	`3612 ****** 9012`
UnionPay	`6212345678901234`	`6-9,11-14`	`6212 ** ** 1234`
RuPay	`8112345678901234`	`6-9,11-14`	`8112 ** ** 1234`

Examples

Input	Output	Card Type
`4123456789012345`	`4123 ** ** 2345`	Visa
`4123456789012345678`	`4123 ** ** 678`	Visa (19)
`5112345678901234`	`5112 ** ** 1234`	MasterCard
`341234567890123`	`3412 ****** 90123`	Amex
`371234567890123`	`3712 ****** 90123`	Amex
`6011000990139424`	`6011 ** ** 9424`	Discover
`3528000012345678`	`3528 ** ** 5678`	JCB
`36123456789012`	`3612 ****** 9012`	Diners Club
`6212345678901234`	`6212 ** ** 1234`	UnionPay
`8112345678901234`	`8112 ** ** 1234`	RuPay
`4123-4567-8901-2345`	`4123 ** ** 2345`	Visa (clean)

Notes

Composes CreditCardFormatter for formatting and MaskFormatter for masking
Formats the card number first, then applies masking to the formatted string
Mask ranges are applied to 1-based positions in the formatted string
Non-digit characters are automatically removed from input
Inputs with fewer than 9 digits are returned as cleaned digits without formatting or masking
Uses CreditCardFormatter for card type detection and formatting