When you start accepting payments for your online shop, your brick-and-mortar store or through any other way you will be receiving a lot of different information one of these items is your Merchant Indeficiation Number (MID).
When it comes to e-Commerce a lot of business settle for the easy option when creating their webshop. Most open-source content management systems, like Shopify have partnered up with fixed payment service providers and those are pre-installed in their settings.
Whenever a recurring payment takes place, the customer has given his or her approval to process the payment once a month, or per agreed payment term for a certain service to be delivered. The acquiring bank then processes that payment through the gateway as per agreed date. This can be done through the credit card or directly through the bank via Direct Debit.