In the course of a survey among 21,000 prospective clients who consciously do not engage in online shopping, 62% referred to insufficient security in payment transactions and almost half of the respondents stated that their preferred payment method is often not available and that they do not want to pass sensitive data on to third parties, namely payment service providers.

Since cash is still popular in the retail industry - 82% of all purchases are paid in cash - the Cash Payment Solutions GmbH developed the idea to introduce cash money into the online business. After the order has been completed, the customer receives a PDF file including a barcode. The customer then takes the barcode to a selected retail partner (drug store, supermarket, etc.) and pays the purchase in cash. The online shop will be informed in real time and can dispatch the ordered goods.

To implement this payment method in a way that is cost- and time-efficient for online shops , it is neccessary to provide expansions for common online shop systems that offer possibilities for easy implementation. Due to the large number of online shop systems, the complete and individual implementation for each system would be too complex. The basic functionality of the plugin - the communication via  Barzahlen API - is thus meant to be developed seperately and then provided. 

In the first step, all payment methods that are already available at the market are meant to be observed to illustrate the relevance of cash as a payment method. Subsequently, the disadvantages of the individual full development compared to the development with SDK need to be illustrated. The goal is the design and the development of a PHP SDK and of application examples for the creation of online shop expansions.