Automated Clearing House:

Automated Clearing House (ACH) is the name of an electronic network for financial transactions in the United States. ACH processes large volumes of both credit and debit transactions which are originated in batches.

ACH credit transfers include direct deposit payroll and vendor payments. ACH direct debit transfers include consumer payments on insurance premiums, mortgage loans, and other kinds of bills. Businesses are also increasingly using ACH to collect from customers online, rather than accepting credit or debit cards.
Uses of the ACH payment system
• Debit card transactions
• Direct deposit of payroll, Social Security and other government benefits, and tax refunds
• Direct debit payment of consumer bills such as mortgages, loans, utility bills, and insurance premiums, rents, and any other regular payment.
• Business-to-business (B2B) payments
• E-commerce payments
• Federal, state, and local tax payments
• Bank Treasury management departments sell this service to business and government customers