Definition of ACH
ACH stands for Automated Clearing House, a US electronic funds transfer network that processes bank-to-bank transactions in batches. ACH enables the movement of money between bank accounts without requiring checks, wire transfers, or cash. It is the infrastructure behind direct deposit of payroll, bill payment, business-to-business transactions, and direct debit collections. ACH is operated by Nacha and is used for hundreds of billions of dollars in transactions annually.
How ACH Transfers Work
ACH transactions are processed in batches throughout the business day. The originating bank sends a transaction file to the ACH network, which routes it to the receiving bank. Settlement typically occurs within one to three business days for standard ACH, though Same-Day ACH is available for faster settlement within the same business day. Both credits (pushing money to another account) and debits (pulling money from another account) can be processed through ACH.
ACH Credits vs. ACH Debits
ACH credits push funds from the originator to the recipient, for example when a company deposits payroll into employee bank accounts. ACH debits pull funds from the recipient's account with prior authorization, for example when a subscription company automatically collects a monthly payment from a customer's checking account. ACH debits require that the account holder has authorized the transaction in advance, typically through a signed agreement or digital authorization.
ACH Explained for a General Audience
ACH is the behind-the-scenes system that makes most electronic money transfers possible in the United States. When an employer deposits your paycheck directly into your bank account, that is ACH. When a subscription bill is automatically deducted from your checking account, that is ACH too. It is slower than a wire transfer but much less expensive, making it the preferred method for recurring, high-volume payments where speed is less critical than cost.
ACH in B2B Payments
ACH is widely used in B2B payments because it is cost-effective for large or recurring transactions. Unlike credit card payments, which carry interchange fees of 1.5% to 3%, ACH transactions typically cost a flat fee of a few cents to a few dollars regardless of transaction size. For companies collecting large recurring payments from business customers, ACH significantly reduces payment processing costs while providing reliable, automated collection.
ACH and Recurring Revenue Collection
For SaaS and subscription businesses, ACH direct debit is a preferred method for collecting recurring subscription payments from business customers. It allows companies to automatically pull payment from customer accounts on billing dates without requiring manual action from either party. This reduces late payments, improves cash flow predictability, and reduces the administrative burden of chasing invoices. Setting up ACH authorization at contract signing makes ongoing collections seamless.
ACH Returns and Failures
ACH transactions can fail due to insufficient funds, incorrect account information, account closures, or authorization disputes. A failed ACH return typically takes one to three business days to come back to the originator. Companies relying on ACH for collections must have processes in place to handle returns efficiently, retrying failed transactions, alerting customers, and escalating persistent non-payment through collections workflows.
Summary
ACH is the electronic bank transfer network that powers the majority of US domestic business payments. It is cost-effective, reliable, and well-suited for recurring B2B payments, payroll, and subscription billing. For SaaS and subscription businesses, ACH direct debit is a preferred collection method that reduces fees, improves automation, and makes recurring revenue collection more predictable. Understanding ACH mechanics is essential for finance teams managing payment operations at scale.
