Using a "fake card" in a development allows developers and testers to conduct a payment processing transaction. Here are a few reasons why a fake card might be used for development:

• Testing without Real Transactions: Using real credit card information in a testing environment could pose security risks and is often against the terms of service of payment gateways. Therefore, developers use fake cards to simulate transactions without the need for actual financial transactions.
• Avoiding Charges: In a development environment, developers want to avoid making real charges to credit cards while testing the functionality of their applications. Fake credit cards allow them to test payment processing without incurring actual costs.
• Scenario Testing: Developers may need to simulate different scenarios, such as successful transactions, failed transactions, chargebacks, etc. Using fake credit cards allows them to test a variety of scenarios without affecting real financial accounts.
• Compliance and Security: Handling real financial data comes with legal and security responsibilities. Using fake cards helps developers adhere to compliance requirements and reduces the risk of mishandling sensitive information during the development and testing phases.
• Isolation from Production Systems: Development environments are separate from production environments for security and testing reasons. Using fake cards ensures that any testing or debugging activities don't impact real users or systems.

While fake cards can be useful for testing, developers should follow best practices and adhere to legal and ethical considerations. Additionally, many payment gateways and financial institutions provide specific test card numbers and environments for developers to use during development and testing. These test environments are designed to simulate real transactions without actual financial consequences.

As a developer, you may need an access to the "test" credit card numbers from various brands. We are listing a commonly used credit card numbers from well known brands that you can utilize. The numbers below conforms to Luhn check, and are valid card numbers.

Card Type	Test Number
Visa	4111 1111 1111 1111
	4242 4242 4242 4242
Master Card	5431 1111 1111 1111
	5123 4558 0630 8521
American Express	3782 8224 6310 005
	3714 4963 5398 431
Discover Card	6011 0009 9013 9424
	6011 1111 1111 1117
Diners Club	3670 0102 0000 00
	3614 8900 6479 13
Maestro Debit	6759 6498 2643 8453
	6799 9901 0000 0000 019