Does the Luhn algorithm work for all mainstream credit cards? (Discover, Visa, Mastercard, Amex)

Question

Reference: Luhn Algorithm

The Luhn Algorithm is a great way to quickly verify that the user typed their CC # in correctly.

However, I am concerned that there

Answer 1

Almost.

China UnionPay and one kind of Diners Club card (enRoute) do not use Luhn validation. (LazyOne’s answer is wrong about Diners Club.)

Nearly everyone else does.

Citing Wikipedia's 'Bank card' page:

Don't validate at all:

• Diners Club enRoute
• China UnionPay

Validate with Luhn 2:

• American Express
• Bankcard
• Diners Club Carte Blanche
• Diners Club International
• Diners Club United States & Canada
• Discover Card
• InstaPayment
• JCB
• Laser
• Maestro
• Dankort
• MasterCard
• Solo
• Switch
• Visa
• Visa Electron