Anyone who’s responsible for ACH operations, fraud, or compliance has likely spent the past few months staring at the March 2026 Nacha deadline with a fair amount of dread. Initially announced in March 2024, these new requirements are going to be implemented in two phases (March 20, 2026 and June 19, 2026, depending on the size of the institution) and they mark a fundamental shift from passive observation to proactive, risk-based detection. Gone are the days of next-day manual reports, as the focus moves toward real-time visibility and a defensible operational framework that proves risk is being actively managed, rather than being reacted to.

While the transition is significant, the shift toward compliance is more a matter of strategic alignment than a total system overhaul. Sardine recently convened a panel of experts to translate these broad regulatory mandates into a clear operational roadmap. By stripping away the conflicting information currently circulating in the industry, we identified five essential pillars for building a defensible framework ahead of the 2026 deadlines.

Defensibility as the new north star

The industry often hunts for a “silver bullet” to stop every single fraudulent cent from crossing the wire, but these updates prioritize a different, more realistic reality. Perfection in fraud remains a pipe dream, and Nacha’s framework acknowledges that. It instead emphasizes that institutions maintaining active, informed watches over their transactions is paramount.

Regulators require a defensible operational approach. This standard places a premium on “processes and procedures reasonably intended to identify” fraud, meaning your logic and internal documentation carry as much weight as the monitoring software itself. If a threat surfaces, you must provide a repeatable game plan that stands up to scrutiny. To maintain compliance, institutions must:

• Pinpoint the ACH risk profile: Identify specific vulnerabilities within your unique payment flows.
• Maintain a continuous watch: Treat monitoring as an active effort rather than a “set it and forget it” task.
• Execute a response: Follow a clear playbook the moment red flags appear.
• Document the “why”: provide auditors with the exact reasoning behind every risk decision.

As the panel emphasized, success rests on visibility: Hailey Windham noted that the rule is less about a perfect catch rate and more about the quality of the net. “This rule isn’t about eliminating fraud entirely, it’s about demonstrating that your institution understands its ACH risk, it’s monitoring appropriately, and is prepared to respond when risk indicators appear.”

Documentation serves as the ultimate anchor for this requirement. If you cannot explain the process, an examiner will assume it doesn’t exist. Not every bad actor has to be caught, but there needs to be proof that you were actually looking for them.

Real-time visibility and the next-day lag

The industry is moving away from the “day-after” mindset that has continued to persist, even in the time of fast-moving fraud. Historically, fraud teams have relied on next-day reports or manual batch reviews performed well after a transaction is cleared. This delay creates a window of opportunity for fraudsters to move funds through multiple accounts before the first alarm even sounds.

The webinar highlighted a move toward a more agile model including:

• Inline monitoring: Scrubbing transactions for risk before they post to an account.
• Pre-processing controls: Using machine learning to assign risk scores to payments in flight.
• Behavioral Signals: Identifying anomalies such as suspicious session activity or account age at the moment of origination.

This shift stems from the new Nacha focus on False Pretenses. This category covers payments induced by misrepresenting the identity or authority of the receiver. Because these scams often involve authorized account holders being tricked into sending funds, waiting for the traditional "unauthorized" return code is a losing strategy. By the time that code arrives, the trail has usually gone cold.

Stacey Gross captured the industry’s trajectory when she stated: “For me, when I look at the future of what fraud monitoring looks like, it is real time and proactive.” 

This marks a departure from the “set it and forget it” mentality of the past. It moves the focus away from the back-office reporting and toward the same level of rigorous, inline scrutiny that has already become the standard for instant payments.

Understanding network roles

A major point of confusion in all of this is where responsibility inevitably falls. Many institutions assume that because they use a third-party processor, the monitoring burden is off their plate. However, accountability in the ACH network is tied to each defined role (ODFI, RDFI, Originator, or TPSP) rather than job title or vendor list. Crucially, RDFIs (Receiving Institutions) are no longer passive observers and are now mandated to monitor incoming ACH credits.

Before rewriting every procedure in the handbook, teams should take a step back and ask:

• What ACH roles do we play? Many banks play more than one.
• Are we in Phase 1 (March 20, 2026) or Phase 2 (June 19, 2026)? This depends strictly on your 2023 volume.
• Where does monitoring responsibility sit? You need to know exactly who is watching which gate.
• How is that documented? If it isn’t on paper, it didn’t happen.

Stacey Gross clarified that these designations are the foundation of compliance: “It depends on what role that you play in the transaction…very clearly, if you align to a defined role that is in the scope for these rules, then you are accountable to the rules.”

One signal is never enough

In the face of authorized fraud and coordinated mule activity, single data points are essentially useless. An IP address on its own is just a digital footprint that any fraudster can mask with a VPN. Even when accounts are tokenized, you have to look at the surrounding metadata to find the hidden links that indicate a coordinated attack.

The era of static, single-trigger alerting is long gone and in its place, effective fraud detection must now be:

• Behavioral: Watching for changes in how a user interacts with the system.
• Contextual: Comparing a transaction against the historical norms of that specific account.
• Network-aware: Using industry signals like the R17 return code. If an RDFI flags a payment as “questionable”, that is a flare for the ODFI to start an investigation.

Sathya Gopalakrishnan highlighted this shift toward aggregated intelligence, explaining that “it is also important to understand that not one data point gives the full picture, so it is always important to look at it from multiple steps.”

Reassessing gaps versus actual compliance

The good news is that most institutions are already quite good at stopping fraud before it gets a chance to settle. Transaction monitoring and risk decisions are already baseline practices for any modern healthy bank. The 2026 updates are less about reinventing the wheel and more about ensuring that wheel is balanced and the alignment is well documented for auditors.

While the “defensibility” requirement sets the standard, the actual implementation often reveals that the leap to compliance is shorter than it appears. It is a matter of formalizing the silent work your team is already doing. Hailey Windham closed the discussion with the reminder that everyone is already working with a head start: “Most of you are already doing more than you realize…the important thing is having a thoughtful, risk-based approach, and being able to explain and document your process.”

The final hurdle is simply translating institutional “gut feelings” into a systemic risk-based approach. If you can bridge the gap between your operational habits and your written procedures, you clear the highest bar of the 2026 mandates.

Immediate next steps for institutions

• Map the roles: Align your current monitoring against your actual ACH roles (ODFI/RDFI) and volume thresholds to confirm your Phase 1 or Phase 2 status.
• Review the policy vs. practice: Ensure your written manuals actually reflect the real-time checks your team is performing.
• Identify the “blind spots”: Use the Nacha 10-question scorecard to find the small procedural holes that could trip up an audit, rather than searching for a total system overhaul.
• Check out our new guide that dives into False Pretenses here.