To set up ACH payments to vendors, you need three things in place: each vendor’s banking details plus a signed authorization, a bank or payment platform willing to originate the transfers for you, and a validated test transaction before real money moves. Once those are lined up, most businesses pay less than 50 cents per payment and see funds settle within one to two business days.
What to Collect from Each Vendor
Every ACH payment requires three pieces of information from the vendor: the legal business name exactly as it appears on their bank account, the nine-digit ABA routing number that identifies their financial institution, and their bank account number.1American Bankers Association. ABA Routing Number You also need to know whether the account is checking or savings. Specifying the wrong type will bounce the payment back.
Collect a completed IRS Form W-9 from every vendor before you send them a dollar. The W-9 captures the taxpayer identification number you’ll need for 1099 filings at year-end and tells you the vendor’s tax classification. If a vendor refuses to provide one, you’re required to withhold 24% of each payment and send it to the IRS as backup withholding.2Internal Revenue Service. Backup Withholding
Never let vendors email their bank details. Email is easy to intercept, and a compromised routing or account number can quietly redirect payments to a fraudster. Use a secure vendor portal, encrypted file sharing, or an onboarding workflow inside your accounting software. Apply the same precaution when an existing vendor tells you they’ve switched banks.
Get a Written ACH Authorization
NACHA Operating Rules require written authorization before you can originate any ACH payment to a vendor’s account.3Nacha. About Us For business-to-business payments using the CCD entry class, that means a signed written contract between your company and the vendor. Most banks and accounting platforms provide standardized templates you can customize.
The authorization should state the vendor’s account type, the nature and frequency of payments, and your right to reverse incorrect entries. Store every signed authorization securely for at least two years after the date of the last payment, which is the NACHA retention requirement. When a vendor changes banks or closes an account, execute a fresh authorization before the next payment cycle. Sending money to a closed account on the strength of an outdated form creates liability for you and delays the vendor.
Validate the Account with a Prenote
Before sending a live payment to any new vendor, send a prenote first. A prenote is a zero-dollar test transaction that validates the routing and account numbers against the receiving bank’s records. If the details are wrong, the prenote returns within a few business days and you catch the error before real money is in flight. Once the prenote clears without a return or a notification of change, the account is confirmed and ready for funded transactions. The step adds a short delay to your first payment and eliminates the single most common reason ACH payments fail.
Pick Who Will Originate Your Payments
To send ACH payments, you need a relationship with an Originating Depository Financial Institution, which in practice is usually your business bank. Most commercial banks provide an online portal where you can upload NACHA-formatted payment files or key in individual transactions. Bank-direct options tend to have strong security controls but sometimes lack tight integration with your accounting software.
Third-party payment platforms such as QuickBooks or Bill.com are the alternative. They connect to your bank in the background, format the NACHA files for you, and can match outgoing payments to open invoices in your accounts payable ledger. The tradeoff is an extra layer between you and the bank, which can slow troubleshooting when a payment goes sideways.
A 2022 AFP survey found the median cost of sending or receiving an ACH payment falls between 26 and 50 cents for most businesses, dropping to between 11 and 25 cents for companies with $5 billion or more in annual revenue.4Nacha. ACH Costs Are a Fraction of Check Costs for Businesses, AFP Survey Shows Some providers add monthly platform fees on top of the per-transaction rate, so compare total cost at your expected volume rather than the sticker price per payment.
Send the First Payment and Track It
Once vendor profiles are loaded and authorized, the payment itself is straightforward. Open the payment module in your banking portal or accounting software, select the invoices or amounts, and review the details. Most systems let you batch multiple payments into a single transmission file, which saves time on a payment cycle covering several vendors.
Before you authorize, verify the total dollar amount against your accounts payable records. A transposed digit or a duplicate invoice becomes a real problem once the money leaves your account. After submission, the system assigns a unique 15-digit trace number to every transaction in the batch.5ACH Guide for Developers. ACH File Details That trace number is how you follow the payment through the network, and it’s the first thing your bank will ask for if you need to research a missing one.
Save the confirmation report your bank or processor issues once the file is accepted. Those reports create the audit trail linking each debit from your account to the corresponding credit in a vendor’s account, and they make month-end reconciliation far less painful.
Standard ACH payments settle within one to two business days after submission.6Nacha. The ABCs of ACH Timing depends on when you submit relative to your bank’s cut-off and which settlement window applies. Weekends and bank holidays pause the clock, so a Friday afternoon submission won’t settle until Monday at earliest. When timing genuinely matters, Same-Day ACH processes the payment inside the same business day for an added fee, with the latest processing window accepting files submitted by 4:45 PM Eastern Time.7Nacha. Expanding Same Day ACH
Handling Returns and Reversals
When a transaction can’t be completed, the receiving bank sends back a return code explaining why. Common reasons include insufficient funds in your account, a closed or invalid vendor account, or an account that’s structurally frozen. Returned payments typically carry a fee of $2 to $30 depending on your bank, and the money is credited back to your account. Watch the return patterns closely. Repeated returns for unlocatable or invalid accounts usually signal that vendor onboarding needs tighter validation, and a run of them can raise flags with your bank about the quality of your ACH origination.
Reversals are narrower than most people assume. NACHA rules allow you to reverse an ACH payment only when the reversal reaches the receiving bank within five banking days of the original settlement date, and only for specific reasons: duplicate payment, wrong recipient, wrong dollar amount, a debit that went out earlier than intended, or a credit that went out later than intended.8Nacha. Reversals and Enforcement A reversal request is not a guaranteed clawback. If the vendor’s account has already been drained or closed, you’ll need to recover the funds by other means. You can’t use a reversal because you changed your mind or a dispute came up after the fact. Anything outside the permitted reasons means contacting the vendor directly and asking them to return the funds.
Fraud Controls Worth Turning On at Setup
Two controls make the biggest difference for ACH fraud, and most business banks offer both.
Dual control requires two people to complete any ACH transaction. One creates the payment, and a second authorized employee reviews and approves before the bank sends it. This catches external fraud attempts and internal mistakes alike: an extra zero on an amount, a vendor profile quietly edited to redirect funds, a fake invoice that slipped past the first reviewer. Set a maximum dollar threshold for automatic approvals so unusually large transactions always require manual review.
An ACH debit filter or block addresses the other side of your account. Vendor payments you originate are ACH credits leaving your account, but your account is also exposed to incoming ACH debits, where someone else pulls money from you. A debit filter lets you maintain a list of approved companies allowed to debit your account and blocks everything else. If your business doesn’t regularly authorize third parties to pull funds from your operating account, a blanket ACH debit block eliminates the risk. Some banks also offer ACH Positive Pay, which flags any incoming ACH that doesn’t match a pre-approved list for your review before it posts.
Tax Reporting Still Applies
Switching to ACH doesn’t change your tax reporting obligations; it just makes the tracking cleaner because every payment carries an electronic record. If you pay $600 or more during the year to an unincorporated vendor for services, you must file a Form 1099-NEC reporting those payments.9Internal Revenue Service. Am I Required to File a Form 1099 or Other Information Return Payments to C-corps and S-corps are generally exempt, except for legal and medical services, which require a 1099 regardless of the vendor’s corporate structure.
This is why collecting the W-9 before the first payment matters. It tells you the vendor’s tax classification and TIN, both of which you need to file the 1099 correctly, and it lets you skip the 24% backup withholding that otherwise applies.2Internal Revenue Service. Backup Withholding Starting with tax year 2023, businesses filing 10 or more information returns must file them electronically.9Internal Revenue Service. Am I Required to File a Form 1099 or Other Information Return If you’re paying enough vendors by ACH to justify the switch from checks, you almost certainly meet that threshold.