Electronic check processing is an online payment option for businesses to collect from This merchant account gives them the ability to use the ACH network to. An eCheck is an electronic payment where the money is directly withdrawn from your checking account, just like writing a check. When you use eCheck, you get. The payment might be sent instantaneously or if you use a third party you might opt for paying for shopping by echeck, a slower method that. Buyers and sellers pay and get paid by eCheck in electronic transactions similar to tradtional banking. By Victoria Rosenborg, Marsha Collier. Approval can happen in the matter of days. Service-based businesses can expand marketing, accept payments, and improve customer retention using one SaaS platform. What is an Institution Number?