ACH stands for Automated Clearing House. The clearing house is a computer network that connects all U.S. financial institutions and enables the secure and efficient movement of money and information directly from one bank account to another. It’s a way to make payments without using checks or wire transfer, credit card networks, or cash. The National Automated Clearing House Association (NACHA) develops the rules and standards for the ACH network. According to NACHA:
In 2018, the ACH Network processed nearly 23 billion payments, marking the fourth consecutive year in which it added more than 1 billion new payments. Those include Direct Deposit via ACH of salaries, dividends and Social Security and other government benefits, and Direct Payment via ACH for bill payments including utilities and mortgages, as well as charitable giving, tuition, subscription services, and person-to-person (P2P) and business-to-business (B2B) payments. The total value of these payments exceeded $51.2 trillion.nacha.org
ACH transactions require your authorization for your employer or a vendor to access your bank account directly. It is a safe way to pay and receive funds and is faster and more cost effective than paper checks.
ACH transactions are not immediate. They do have a clearing time, around three days. If you want to stop a regularly schedule ACH payment, just notify the bank at least three days before the funds are scheduled to be debited from your account.