Nacha is casting a wider net in 2026, expanding the scope of institutional liability to include authorized "False Pretenses" and Credit-Push fraud. This comprehensive guide provides the technical and operational framework required to navigate these new monitoring standards, automate mandated entry descriptions, and leverage proactive AI infrastructure to ensure audit-ready compliance.
TL;DR
- March 20, 2026 kicks off Nacha’s new fraud monitoring requirements (Phase 1) and new PAYROLL / PURCHASE company entry descriptions, with Phase 2 following in June 2026.
- The rules push banks, credit unions, and originators from return‑rate checks to risk‑based monitoring of both unauthorized and “false pretenses” (scam‑induced) payments across ACH credits and debits.
- To stay ahead, you need to:
- Use device intelligence and behavioral data to detect scams before the transaction ever hits the file.
- Build a 360° customer view across ACH and other rails, not just return codes.
- Refresh ACH strategies with industry best‑practice patterns, not bespoke rules per team.
- Invest in consortium data to see fraud rings and mules your institution alone will never see.
- Apply AI to fraud operations, not just scoring, but also prioritizing queues, tuning rules, and accelerating investigations.
- DataVisor’s ACH fraud solution is built around four pillars—out‑of‑box rules, device intelligence, consortium signals, and AI agents—that directly map to Nacha’s 2026 expectations while improving detection, false positives, and analyst productivity.
1. The 2026 Nacha Rule Update: From "Trust" to "Verify"
The ACH network is changing to fight modern fraud. Here is what your business needs to know.
If your business moves money via ACH, whether for payroll, vendor payments, or e-commerce, significant changes are coming.
Historically, the ACH network relied heavily on the honor system. But with the rise of sophisticated scams, Nacha (the governing body of the ACH network) is rolling out a major update to turn ACH into a fully monitored fraud-prevention system.
The goal? To stop not just unauthorized hacking, but also "authorized scams"—situations where you or your customers are tricked into sending money to the wrong person.
Here is a plain English breakdown of what is changing, when it happens, and what you need to do.
The Two Big Changes
The 2026 rule package focuses on two main themes for banks and businesses:
- Mandatory Fraud Monitoring: It will no longer be optional to just "process" payments. Banks and businesses (Originators) must actively monitor for fraud. This includes detecting payments made under "false pretenses" (scams).
- Cleaner Data: New labels for transactions will help banks spot legitimate payments versus suspicious ones.
Timeline: When to Be Ready
The rules roll out in phases. While the biggest changes hit in March 2026, there was an early requirement that started in 2025.
April 1, 2025: The "Response" Rule
What’s happening? If a bank asks for money back (a Request for Return), the receiving bank must respond with a status update within 10 banking days.
Why it matters? In the past, return requests often went into a "black hole." This rule ensures communication happens, even if the answer is "no."
March 20, 2026: Large Organizations (Phase 1)
Who is affected? Only large organizations as defined below:
- Large Originators: Businesses sending 6 million+ ACH payments annually (in 2023).
- Large Receivers: Banks receiving 10 million+ ACH payments annually (in 2023).
What’s required? You must have a system in place to monitor for fraud before and during the transaction. This includes validating that a "new" account for a WEB debit is actually owned by your customer.
New Labels: You must use the standard descriptions PAYROLL for wage payments and PURCHASE for e-commerce payments. This replaces vague descriptions like "PAYMENT" or "MISC."
June 22, 2026: The Market-Wide Rollout (Phase 2)
(Note: The official date is June 19, but since that is a holiday, compliance starts June 22.)
Who is affected? Every organization that originates ACH payments.
What is changing? The fraud monitoring rules extend to all remaining businesses and banks, regardless of transaction volume.
Timeline at a glance
New Concept: "False Pretenses"
This is the most critical definition in the new rules.
Previously, fraud monitoring mostly looked for unauthorized entries—like a hacker breaking into a bank account to steal funds.
The new rules require you to look for "False Pretenses." This covers authorized scams, where a legitimate user is tricked into sending money.
- Example 1 (Business Email Compromise): Your accounts payable team receives a fake email from a "vendor" asking to update their bank details. You authorize the payment, but it goes to a scammer.
- Example 2 (Payroll Diversion): A fraudster impersonates an employee and asks HR to switch their direct deposit to a new "Green Dot" card.
Under the new rules, systems must be designed to help spot these anomalies (e.g., "Why is this vendor suddenly using a different bank?" or "Why are 10 employees switching direct deposits to the same account?").
For the official rule text and FAQs, your primary references should be:
- Nacha Operating Rules – New Rules (Risk Management Topics, Fraud Monitoring Phases 1 & 2, Company Entry Descriptions):
https://www.nacha.org/newrules - Nacha Risk Management & Credit‑Push Fraud Monitoring Resources (including guidance for originators and FIs):
https://www.nacha.org (Risk Management section).
2. The Million-Dollar Question: Who is Liable?
The 2026 rules create a new "Standard of Care," but they do not automatically turn your bank into an insurance policy. It is critical to understand the difference between Compliance and Reimbursement.
- The Compliance Shift (What Banks Must Do)
Banks are now required to build better "burglar alarms." They must have systems to detect if a payment looks like a scam (e.g., a grandmother suddenly sending life savings to a crypto wallet). If they don't have these systems, they are breaking the rules.
- The Liability Reality (Who Pays)
- Unauthorized Fraud (Hacking): As always, the bank generally pays (under Reg E).
- Authorized Scams (Tricked): If you or your employee authorize the payment, you are usually still liable for the loss. The new rules do not override federal laws (like Reg E or UCC 4A) that govern who takes the hit.
However, the stakes are higher. While the rule doesn't force reimbursement, it creates a paper trail. If a business loses money to a scam and can prove their bank failed to monitor for "False Pretenses" as required by Nacha, it opens the door for legal battles.
3. Five strategic moves to make now
Regulators and networks often frame this as “monitor more.” But if you’re a bank or credit union leader, the real question is how to meet Nacha’s expectations in a way that also reduces losses and OPEX—not just ticks a compliance box.
Here are five moves that align with the new rules and give you a durable advantage.
3.1 Put device and behavioral intelligence at the center
Nacha’s focus on false pretenses is a quiet admission that authentication alone is no longer enough. In many 2026‑style scams, the customer:
- Logs in from a trusted device
- Passes MFA
- And still gets coached into sending an ACH payment to a mule account.
What actually changes in those sessions isn’t the password—it’s the behavior.To catch this, leading FIs are:
- Fingerprinting devices across channels (web, mobile, APIs) to spot:
- First‑time or spoofed devices on high‑risk actions
- Remote‑access‑tool signatures
- Device sharing across many accounts
- Layering in behavioral biometrics and interaction patterns:
- Hesitation around beneficiary changes
- Copy/paste into critical fields
- Unusual navigation flows or repeated edits in routing/account details.
These signals let you:
- Flag account takeover (ATO) before files are submitted
- Detect social engineering at the moment of setup, not after the return comes back
- Score sessions and accounts, not just individual entries.
From a Nacha perspective, this is exactly the kind of risk‑based procedure they’re signaling—monitoring for anomalies in how entries are created, not just what’s in the Nacha record.
3.2 Build a 360° customer view across ACH and other rails
The new rules are written for ACH, but fraudsters don’t respect payment silos. They’ll:
- Probe via P2P and RTP,
- Cash out via ACH credits or wires, and
- Wash funds through card, checks, or internal transfers.
If your monitoring is ACH‑only, you’ll see just one frame of a much larger movie.
A defensible 2026‑ready program connects:
- ACH data: SEC codes, company entry descriptions, amounts, timing, returns.
- Customer profile: tenure, KYC, segment, limits, linked accounts, historical counterparties.
- Other rails: Zelle/RTP/FedNow, wires, checks, cards, internal transfers, even digital banking events.
That enables:
- Composite risk scoring: the same customer suddenly:
- Receives multiple payroll credits to a previously dormant account, and
- Starts sending outbound ACH credits and P2P transfers to new counterparties.
- Mule detection: inbound ACH patterns + outflows across other rails reveal money‑movement hubs no single rail would flag on its own.
Nacha’s own guidance for originators emphasizes lifecycle monitoring, account validation, and routine/red‑flag reporting—all of which work better when you have a unified customer view rather than siloed ACH dashboards.
3.3 Refresh your ACH strategy with industry best‑practice patterns
Many institutions still treat ACH fraud rules as a collection of local, one‑off rules:
- ATO rules built by online banking teams
- BEC rules owned by treasury
- Return‑rate thresholds defined by operations.
Under the 2026 rules, that fragmentation becomes a liability. Examiners and Nacha can now ask:
- “Show me your documented, risk‑based procedures for unauthorized and false‑pretenses ACH entries.”
- “How do you review and update these annually?”
Instead of reinventing the wheel, you want codified, industry‑tested patterns:
- Use‑case‑specific strategies for:
- ACH kiting
- Payroll diversion and vendor impersonation
- New‑account / synthetic identity ACH abuse
- First‑party and mule‑enabled fraud.
- Lifecycle‑based playbooks for:
- Onboarding & account changes
- File upload and payee maintenance
- Inbound credit monitoring and returns.
The goal is to move from dozens of tribal rules to a small number of curated ACH patterns that:
- Are documented
- Map neatly to ODFI vs RDFI responsibilities
- Can be tuned and reviewed on a predictable cadence.
Competitor content is already pushing banks toward this kind of structured playbook. The differentiator is how quickly you can operationalize it without putting everything back on your engineers.
3.4 Invest in consortium data
Nacha’s rules push everyone to monitor more, but each institution still only sees its own book. That’s a problem because:
- Mule accounts often hop between institutions.
- Fraud rings reuse devices, emails, IPs, and entities across many banks and CUs.
- Single‑FI models struggle to spot low‑velocity, cross‑network patterns that are benign locally but toxic in aggregate.
Modern fraud programs are therefore leaning on anonymized consortium data:
- Shared signals and reputations (device, account, identity attributes) across participating FIs.
- Graph‑based views that reveal mule clusters and ring structures that no one FI could see alone.
- Faster pattern discovery when a new scam or mule network emerges on another rail or in another region.
Nacha’s own risk management guidance encourages broader data‑sharing and layered controls to combat credit‑push fraud, recognizing that originators and RDFIs can’t solve this in isolation.
For 2026 readiness, consortium data is one of the most efficient ways to:
- Upgrade from institution‑only models to a network‑effect defense.
- Show auditors and Nacha that your “risk‑based procedures” incorporate external signals, not just local returns.
3.5 Put AI to work in fraud operations, not just in models
Most market commentary on Nacha’s rules stops at “use machine learning.” That’s table stakes. The harder part—and the real cost center—is fraud operations:
- Which alerts to work first?
- Which rules are causing noise vs value?
- How do we keep up with daily tuning while documenting changes for audit?
A 2026‑ready program should use AI to assist fraud ops and strategy, not just scoring:
- Dynamic rule and parameter tuning
- AI agents monitor detection KPIs and recommend rule threshold changes or new combinations.
- They can propose A/B tests and simulate impact before you push to production.
- AI‑assisted triage and investigation
- Rank alerts by likelihood of fraud and potential loss.
- Auto‑summarize case context (customer 360, device, counterparties, third‑party signals) so analysts spend time deciding, not assembling data.
- Continuous program review
- Generate periodic reports that show:
- Rule performance (alert rate, precision, recall)
- Model performance by scoreband
- Emerging ACH fraud patterns and mule clusters.
- Generate periodic reports that show:
This directly supports Nacha’s requirement for ongoing review and adjustment of fraud monitoring programs and gives you exam‑ready evidence of how your controls evolve with the threat landscape.
4. How DataVisor helps you operationalize Nacha’s 2026 rules
DataVisor’s ACH fraud solution was designed around the same pressure you’re now seeing from Nacha and regulators: catch more scams and ATOs, reduce noise, and give examiners something concrete to review.
At the core of our approach are four pillars:
Because the ACH solution is built on DataVisor’s broader multi‑rail fraud and AML platform, you can:
- Start with ACH‑focused compliance for the 2026 rules, then
- Expand into wires, RTP/FedNow, checks, cards, onboarding, and AML as you consolidate tools and simplify your risk stack.
That positions Nacha’s 2026 changes not just as a compliance headache, but as a forcing function to modernize:
- From return‑rate monitoring to proactive, multi‑signal detection
- From static rules to AI‑assisted, continuously tuned strategies
- From institution‑only views to consortium‑powered, cross‑rail intelligence.
Get help from an expert, reach out today.
