ACH is the most common way to transfer money between bank accounts in the US. Learn how ACH payments work and how they compare to other payment methods.
Last updated:
October 2, 2024
12 minutes
Your customers want to move money—to pay you, to purchase goods and services, to fund their new accounts—and ACH is a tried-and-true way for them to do it.
In fact, it’s the most common way to transfer funds in the United States. According to the Federal Reserve, it accounts for about 70% of all US payments by dollar value.
As payment methods go, ACH is cost-effective, and the user experience is continually improving. But before you start building, you may want to ask yourself these questions:
If you’re a decision maker at a tech company who’s thinking about whether and how to offer ACH to your customers, this guide is for you.
In it, we’ll briefly cover the history of ACH and define common terms. We’ll walk you through an ACH payment and talk about how it works for tech companies and their customers. Finally, we’ll offer three simple steps to get started.
ACH stands for Automated Clearing House; it’s a way to transfer money electronically between bank accounts without cards, checks, or wires.
ACH was created in the 1970s as a way to control the exploding volume of paper checks used for payroll and bill payments. Processing those checks was slow and resource-intensive for banks, who needed a better solution.
In 1974, the National Automated Clearing House Association (NACHA) was formed to administer ACH in the United States; they’re the source of the rules that all network participants must follow. The US Air Force was the first employer to adopt direct deposit via ACH; today, more than 94% of Americans get their paychecks this way.
Common examples of ACH payments:
Only an authorized financial institution can “originate” an ACH payment on behalf of a payor or payee.
For this reason, tech companies that make ACH payments available to their customers typically partner with a bank or with a banking-as-a-service platform that has one or more bank relationships built in.
When one of your customers initiates an ACH payment through your app or website, a NACHA file is generated. A NACHA file is a set of electronic instructions that triggers an ACH payment when it’s uploaded to your bank’s secure server. Each NACHA file includes information about the ACH payment(s) it describes, including account and routing numbers, direction (debit or credit), and payment amounts.
Only an authorized financial institution can “originate” an ACH payment on behalf of a payor or payee.
Periodically throughout the day, your bank batches the NACHA files they’ve received and sends them to the Federal Reserve. Overnight, the Fed tallies up all the NACHA files they’ve received from their member banks.
The morning of the next business day, the Fed sends a “net amount” to each bank, a single payment that represents all the ACH payments involving that bank’s accounts from the previous day. The Fed also sends instructions about which individual accounts to take money out of and put money into.
Each bank executes the Fed’s instructions, sometimes waiting a day or two before releasing funds to the person or business being paid. And that’s it—ACH payment complete.
There are two kinds of ACH transfers: debits and credits.
For your customers, the distinction is unimportant. For you, it’s important to know the difference, as the two kinds of payments are processed in slightly different ways.
The bank that initiates an ACH transfer is called the Originating Depository Financial Institution (ODFI). The bank on the receiving end of an ACH transfer—whether debit or credit—is called the Receiving Depository Financial Institution (RDFI).
Let’s say you’re the CEO of Lando, a platform that helps landlords manage their rental properties.
One of the services you offer is rent collection: each month, for each of their properties, your customers (landlords) typically initiate an automated ACH debit, “pulling” money from their tenant’s bank account into their own bank account.
Here’s how it works. After a tenant has connected their checking account (from, say, Wells Fargo) and authorized their landlord to debit the account, the landlord sets up a recurring ACH debit for each month’s rent—say, $1000.
Funds typically land in the payee's bank account after 2-5 business days.
Each month, when it’s time for that particular tenant to pay rent, Lando (or actually, their banking-as-a-service platform) creates a NACHA file and sends it to their bank partner (e.g., Thread Bank), who originates ACH transactions on their behalf. Later that day, Thread Bank batches this individual rent payment with dozens or hundreds of other ACH payments they’re originating and sends the batch to the Federal Reserve.
A few hours later, the Fed sends the details of the transaction to both the tenant’s bank and the landlord’s bank, adding the payment amount (a debit for the tenant, a credit for the landlord) to each bank’s daily settlement volume. The funds will be transferred on the morning of the next business day.
Assuming everything goes according to plan, the tenant’s account balance will decrease by $1000 on the morning of the next business day. The landlord’s account balance will increase by $1000 within 2-5 business days—the time it takes the ACH payment to “settle” or “clear.”
Most ACH payments proceed this way: the account and routing numbers have been entered correctly, there’s enough money in the payer’s account, and there’s no reason to suspect fraud.
Because the Fed processes ACH transfers overnight, it’s natural to assume they take, at most, 24 hours to settle in the payee’s account.
The reality is significantly slower: often 2-5 business days. The primary reason is that banks typically wait to release those funds to their customers. That’s because a small fraction of ACH payments are “returned”—that is, they’re unsuccessful. Naturally, both banks and software companies want to mitigate this risk.
There are several other factors that can affect the length of time it takes for an ACH payment to settle:
If your customer initiates an ACH payment after your bank has sent its last daily batch of ACH files to the Fed, the payment will take an extra day to process.
Say your customer initiates an ACH bill payment to their mobile phone carrier at 5pm ET. However, their bank’s ACH cut-off time is 4pm ET. In this case, the funds won’t start to move until the next morning.
Ever wonder why payroll goes out on Friday? It’s because the Fed doesn’t process ACH payments on weekends or bank holidays. If it’s a holiday weekend (e.g., Labor Day), this can add up to three days to an ACH processing period.
Let’s say an employee gets their timesheet approved by payroll on the Wednesday before Thanksgiving. Let’s also assume that the day after Thanksgiving is considered a holiday in their state.
Due to the holiday, that payment won’t begin processing until the Monday following. As a result, the employee may not get paid until at least 6 days after submitting their timesheet.
Banks have the power to set clearing times for ACH payments. For customers they know well and trust, they typically make funds available more quickly. For newer customers and/or those they consider risky, they may choose to wait before releasing the funds.
Imagine a new customer who applied for a bank account yesterday and was approved. Today, they initiate several large ACH debits, attempting to ”pull” thousands of dollars from accounts at other banks. To ensure that these transfers are not fraudulent, their bank may choose to wait a few extra days before releasing the funds.
It won’t surprise you to learn that your customers don’t want to wait to get their money.
In fact, they’ll often decamp to another platform that will pay them faster. In a survey we conducted with the Harris Poll, 67% of American small-business owners said that, as a result of the current economic environment, they need faster access to funds in their bank accounts. In the same survey, 71% said they are open to trying a new banking provider.
Fortunately, there are several ways to make funds available to your customers more quickly when processing ACH payments.
ACH certainly has its virtues relative to other payment methods. But there are tradeoffs, and you’ll want to consider these before you start building.
If you’ve decided that ACH makes sense for your business, you can use these three simple steps to get started:
Unit (our company) helps tech companies build financial products—including ACH payments—into their offering. We’re trusted by nearly 200 leading brands, more than 90% of whom offer ACH through our platform.
If you’ve got questions about ACH or want to schedule a brainstorm, please reach out.
Originally published:
April 5, 2023
Frequently asked questions
For your customers, ACH transfers are relatively straightforward.
There are a few ways to encourage customers to pay by ACH:
Check out our guides page to learn more about embedded finance