What is ACH Payment?

What Is an ACH Payment?

ACH stands for Automated Clearing House, and an ACH payment is an electronic bank-to-bank transfer processed through the ACH network in the United States. If you are based in the UK, the closest equivalent is the BACS payment system -- both are batch-processing networks designed to handle large volumes of routine bank transfers efficiently and at low cost.

ACH payments are the backbone of routine financial transactions in the US. If an American employee receives their salary via direct deposit, that is an ACH payment. If they pay their electricity bill through their bank's online bill pay service, that is likely an ACH payment too. The ACH network processes billions of transactions each year, moving trillions of dollars between bank accounts.

How ACH Payments Work

The ACH network is operated by Nacha (the National Automated Clearing House Association) and processes payments in batches rather than individually. Here is how it works:

The Two Types of ACH Payment

ACH transactions come in two flavours:

• ACH Credit -- the payer pushes money to the recipient's account. This is used for payroll, vendor payments, and tax refunds. The payer initiates the transaction.
• ACH Debit -- the recipient pulls money from the payer's account, with the payer's prior authorisation. This is used for bill payments, subscriptions, and loan repayments. The recipient initiates the transaction.

The Processing Cycle

ACH payments are collected into batches throughout the day and processed at set intervals. The traditional ACH cycle takes one to two business days -- the originator submits the transaction, it is processed through the ACH network overnight, and the funds settle the following business day. Nacha has introduced Same Day ACH, which allows faster processing with multiple settlement windows throughout the day, but it comes with higher fees.

Authorisation

For ACH debit payments (where a business pulls money from a customer's account), the customer must provide explicit authorisation. This can be a signed form, an online agreement, or a recorded verbal authorisation over the phone. The authorisation must specify the amount, frequency, and the customer's right to revoke it. Without proper authorisation, the payment can be disputed and returned.

Why Businesses Use ACH Payments

ACH payments are enormously popular with US businesses for several practical reasons:

• Very low cost -- ACH transactions typically cost between 20 cents and 1.50 dollars per transaction, compared to 2 to 3 per cent for credit card payments. For a business processing thousands of payments, the savings are substantial.
• Ideal for recurring payments -- subscriptions, memberships, loan repayments, and regular invoices can be automated with ACH debit, reducing manual effort and improving collection rates
• High capacity -- the ACH network can handle millions of transactions per day with reliable, consistent processing
• Broad reach -- virtually every bank account in the US is accessible through the ACH network
• Good for high-value payments -- unlike card payments, ACH has no meaningful transaction limits, making it suitable for large B2B payments and high-ticket consumer transactions

ACH vs UK Payment Systems

If you are a UK-based business dealing with US customers or operations, it helps to understand how ACH compares to UK equivalents:

• ACH Credit is similar to a UK Faster Payment or BACS credit -- the payer pushes money to the recipient
• ACH Debit is similar to a UK Direct Debit -- the recipient pulls money from the payer with authorisation
• ACH processing times (1-2 days, or same-day) are comparable to BACS (3 days) but slower than Faster Payments (seconds)
• ACH fees are broadly similar to BACS fees -- low and flat-rate, making them economical for high volumes

One important difference is consumer protection. In the UK, the Direct Debit Guarantee gives consumers an immediate right to a full refund for any payment taken in error. US ACH debit has a return window (typically 60 days for consumer transactions), but the protections are structured differently and vary depending on the type of transaction.

ACH Payments and Telephone Payments

ACH payments and telephone payments intersect primarily in two scenarios. First, businesses that collect recurring payments from US customers may set up ACH debit authorisations over the phone. This involves collecting the customer's bank routing number and account number during the call, along with verbal authorisation to debit their account. Nacha rules require that this verbal authorisation be recorded and that the customer be informed of the payment terms.

This creates a data sensitivity parallel to card payments. While routing and account numbers are not subject to PCI DSS (which covers only card data), they are still sensitive financial information that should be handled securely. Recording calls that contain bank account details creates similar risks to recording calls with card data -- the information is captured in the audio and must be protected.

Second, businesses may take one-off ACH payments over the phone as an alternative to card payments, particularly for larger amounts where card processing fees would be significant. The customer provides their bank details, the agent processes the payment, and the funds settle within one to two business days.

For UK businesses with US customers calling to make payments, understanding ACH is important because it is often the most cost-effective way for those customers to pay. Offering ACH as an alternative to international card payments or wire transfers can reduce costs for both parties.

Practical Considerations

• Ensure proper authorisation for ACH debit payments. Nacha rules are specific about what constitutes valid authorisation, and failing to comply can result in returns, fines, and loss of ACH processing privileges.
• Handle bank account details securely. While not governed by PCI DSS, routing and account numbers should be protected with the same care as card data.
• Plan for returns. ACH payments can be returned for various reasons -- insufficient funds, account closed, unauthorised transaction -- and your processes need to handle these efficiently.
• Understand the timing. ACH is not instant. If you need confirmed funds before providing goods or services, factor in the settlement time.
• If you are a UK business new to ACH, work with a payment processor experienced in US payment methods. The regulatory and operational requirements are different from the UK and getting them wrong can be costly.

ACH payments are a cornerstone of the US payment system, much like BACS and Direct Debit are in the UK. For any business that deals with US customers, employees, or suppliers, understanding how ACH works -- its strengths, its limitations, and its rules -- is essential for efficient, compliant payment processing.