(ABN AMRO, ASN Bank, Friesland Bank, ING Bank, Knab, Rabobank, RegioBank, SNS Bank, Triodos Bank, Van Lanschot)
iDEAL is an e-commerce payment system used in the Netherlands, based on online banking. Introduced in 2005, this payment method allows customers to buy on the Internet using direct online transfers from their bank account.
IDEAL remains by far the most popular method for online payments in the Netherlands, well beyond credit card use, and was used for 54% of all Dutch online payments in 2014.  The service processed 4.5 million transfers in 2006, 15 million transfers in 2007, 28 million transfers in 2008, 45.4 million in 2009, 68.8 million in 2010, 93.8 million in 2011, 117.2 million in 2012 and 142.5 million in 2013. iDEAL is owned by the Dutch organization Currence, which also owned PIN and Chipknip.
The participating banks in iDEAL are ABN AMRO, ASN Bank, Friesland Bank, ING Bank, Knab, Rabobank, RegioBank, SNS Bank, Triodos Bank and Van Lanschot. Together these serve the vast majority of the Dutch online banking market.
iDEAL offers merchants a real-time payment method (publicized as low-cost and virtually risk-free) to accept internet payments. For customers, iDEAL uses the same environment as their banks' online banking sites. A high level of security is realized by using two-factor authentication (2FA), such as a challenge-response access token based on the chip embedded in the debit card or ATM card. Furthermore, no sensitive information is being shared with the merchant, such as credit card numbers. There is no chargeback right however, which can be considered a disadvantage for the consumer using this payment method. This is considered an advantage to the merchants.
iDEAL works as follows:
- Merchant offers iDEAL as payment method
- Consumer selects iDEAL and selects his bank
- Consumer is redirected to his bank's login page
- Participating bank displays transaction data
- Customer enters account number and signs the transaction digitally using a 2FA token
- Bank authorizes transaction in real-time, deducting the amount directly from the consumer's account (if there is not enough balance, the transaction will be refused)
- Merchant received real-time confirmation of the payment by the bank
- Consumer is redirected back to the merchant page with a confirmation that the payment has been successful
iDEAL payments make use of the online banking environment of participating banks and therefore make use of the extensive safety measures of the individual banks. While the transactions themselves are widely considered to be safe, iDEAL transactions could technically be regarded as cash payments between customers and suppliers, to which the bank is no party and offers no insurance. This means that iDEAL payments cannot be reversed when, for example, a webshop fails to deliver. If a user suspects fraud, their only option to get paid money back, is to make a case with their bank, in which the burden of proof lies with the customer and results are unsure. For purchases from untrusted suppliers, other methods of payment can have benefits.
Although banks have been joining efforts to limit technical failures of the system, users (especially sellers) have complained about regular down time. In 2014, the average availability of iDEAL was 99.5% for most customer banks. 
- http://www.internetkassa.nu/ideal-blijft-creditcard-en-online-achteraf-betalen-ver-voor/ ‘iDEAL blijft creditcard en online achteraf betalen ver voor’
- iDEAL payments including numbers of transfers
- Which banks offer iDEAL?
- Can I reverse an iDEAL payment?