ACH is a critical part of the U.S. payment infrastructure, driving a significant portion of transaction volumes and supporting important use cases such as supplier payments, payroll, and many others. Despite competition from newer rails that serve similar purposes, ACH continues to grow at a remarkable pace.

In a PaymentsJournal Podcast, Radha Suvarna, Chief Product Officer of Payments at Finastra, and James Wester, Co-Head of Payments at Javelin Strategy & Research, examined why ACH payments have remained so resilient and valuable, and highlighted the benefits for financial institutions considering offering ACH payments to their customers.

Old Is New Again

When fintech is discussed in the context of modernizing financial services, there is often the assumption that “old” means outdated and “new” means superior. Even though ACH is considered a legacy rail, it’s still highly reliable. It was designed for a specific type of payment: high-volume, predictable transactions that need to be scheduled, such as payroll or bill payments.

“One reason ACH continues to grow is because we can do the planning for those predictable payments,” said Wester. “If you can plan for all of that beforehand, it becomes a great rail for handling those types of payments.”

A Modern ACH Payments Engine

Looking ahead, ACH must become forward compatible alongside other payment rails. Enabling forward compatibility allows the industry to leverage new technologies such as artificial intelligence and integrate them seamlessly with ACH driving improvements in areas such as fraud detection and automation.

So what does a modern ACH payments engine look like from an operational perspective? First and foremost, it must be cloud-native and modular. It should leverage modern technologies such as microservices and API-based capabilities to connect seamlessly with both upstream and downstream systems. The platform should also be architected to scale volumes up or down as needed, recognizing that ACH doesn’t necessarily need to run continuously throughout the day and has peaks in volumes.

“If we can scale the infrastructure up and down as necessary to drive more efficient total cost of ownership, that would be a significant value add,” said Suvarna. “It would be particularly effective in high volume throughput windows.”

Another important component of forward compatibility is the ability to test new use cases and enable fast experimentation. Smart routing between batch payments and real-time payments, for example, could be offered as a value-added service. To determine whether such capabilities create meaningful impact, organizations need platforms that allow quick testing, with the ability to fail fast or scale successful outcomes.

Financial institutions can rely on a modern ACH solution to integrate with cloud-native and API-driven systems, enabling faster and more efficient launches for new offerings.

It’s also important to note that while the ACH clearing itself has not yet transitioned to ISO 20022, many corporates are already using this for their submissions. A modern ACH platform needs to be able to both handle this, and the eventual migration of the clearing system, seamlessly while accommodating the complex workflows already built around ACH today.

Seeking ROI: Cost

The ROI from ACH can be viewed through two primary lenses: cost and revenue. On the cost side, the first consideration is infrastructure. Platforms built on open-source technologies and modern software stacks are typically less expensive than legacy systems.

The second cost driver is software maintenance and enhancement. As new use cases come up across corporate and retail segments, and as specifications continue to evolve, keeping pace with business-driven and standards-driven changes can be very expensive for legacy platforms.

“There are fewer software developers available to code in some of the older technologies like COBOL,” said Suvarna. “Which means there aren’t that many developers around to make the necessary changes for the foreseeable future. The specialized infrastructure roles where you have a person who really knows the system, those obviously become more expensive.”

The third cost area is operations. Today, exception handling and returns for ACH are often managed separately from other clearing systems. Consolidating these processes into a unified stack—and leveraging technologies like AI—can streamline operations.

“I’m not saying today you can’t deploy AI technologies and machine learning to identify payment repairs, based on the data coming from the legacy ACH capabilities,” said Suvarna. “But the more open modern stack makes it easier and faster.”

Seeking ROI: Revenue

On the revenue side, the primary opportunity for banks lies in differentiation through an enhanced user experience. Examples include offerings such as smart routing between ACH and real-time payments. A second opportunity comes from innovative use cases, where banks create differentiated value propositions around ACH that set them apart from competing institutions.

“When people start talking about ROI, I often hear them talk about revenue first,” said Wester. “But you have to be careful when you talk about system upgrades from a revenue standpoint. To sell it to your leadership, start with the inevitable things that need to be sunsetted and where you can find cost avoidance.”

Finding a Partner

Financial institutions embarking on this modernization journey need partners with experience across multiple implementation domains. A broad perspective helps identify dependencies, eliminate blind spots, and apply best practices. An experienced vendor understands the optimal path forward, knows where common pitfalls exist, and can guide institutions toward scalable, future-ready solutions.

“I like to use the phrase “fish don’t know water is wet,”’ said Wester. “Oftentimes, financial institutions have been running their systems a certain way for so long that they no longer look inefficient, just because they still work. A good partner can come in and say, here are the best practices, here are things where you might be blind to your own issues.”

Finastra, for instance, serves both large enterprise and mid-market client segments. They have built out Global PAYplus for large enterprises and Payments to Go for mid-market clients—both delivered on cloud-native platforms supporting modern ACH clearing. This single, modern payment hub architecture supports multiple clearing types with a common user experience across all rails, and enables forward compatibility, positioning the platform to support future use cases as they emerge.

“At the end of the day, ACH isn’t about just technology modernization,” said Suvarna. “It’s a transformation of business processes around very critical infrastructure that serves many corporate and retail customer needs.”