Orchestrating the US multi-rail instant payment future — FedNow, ACH, and stablecoins

Jeanette Mbungo, Chief Operating Officer at CSG Forte, shares her perspective on a multi-rail payment future, delving into FedNow, ACH, and the stablecoin shift in the US.

How do you see US instant payments and FedNow evolve compared to traditional ACH in 2026? 

It’s the question on many payments professionals’ minds, but I don’t see it as a ‘this or that’, but as a ‘yes and’ scenario. Instant payments and ACH will both have their place in the payment ecosystem, driven by different use cases. 

ACH still commands a massive market share because, for many high-volume, non-urgent batch processes, it remains the most cost-effective tool. We won’t see that change anytime soon. Another aspect many don’t realise is that multiple B2B businesses are still transitioning from paper checks to digital payments, making ACH a strong starting point for companies at that phase of their payment modernisation journey.  

Simultaneously, many industries are seeing strongly justifiable use cases for faster payments. When payments land instantly, both the sender and receiver have peace of mind, knowing exactly where their money is, in real time. 

We’ve seen this exemplified in property management. Historically, there's been a frustrating timing gap that impacts the experience of renters and property managers alike. A tenant submits their rent payment, but with traditional ACH, those funds take a couple of days to clear. The renter is anxious for the rent payment to settle to avoid late fees and to get a clearer sense of their monthly budget. The manager also wants those funds sooner, should they need to pay a local vendor for an emergency repair or push those cleared funds out to the property owners. By using instant payments, that lag is eliminated. Speed is incredibly valuable here, ensuring a simpler, more responsive rental process experience for everyone involved. 

However, ACH is not the only FedNow ‘competitor’. As FedNow evolves, it will need to close the gap with RTP to become the preferred rail for domestic transactions, which means catching up to RTP’s maturity and advanced features, including capabilities like Request for Payment, and increasing transaction limits toward RTP’s current USD 1 million transaction limit. 

Interoperability (with ISO 20022) is another major opportunity, so financial institutions and fintechs can move money easily across both instant rails without adding operational complexity. 

A multi-rail payments strategy could place FedNow as the backbone of domestic US payments. What are the operational challenges of layering FedNow atop legacy ACH, and how can they be mitigated?

The primary challenge isn't the tech of the rails themselves but the orchestration layer above them. When businesses layer a high-speed engine like FedNow atop a batch framework like ACH, they will see friction if they haven't properly prepared operations. 

The first step in preparing operations is understanding them, and I recommend starting with a deep-dive transaction flow audit. Businesses will need to understand how different rails handle settlement, reporting, and crucially, returns. FedNow is final, so there is no inherent return mechanism like the ACH 60-day window, which requires a complete rethink of reconciliation and back-office reporting. 

Second, remember that most operational challenges can be mitigated by partnering instead of building in-house. For many businesses, building a bespoke FedNow integration that communicates seamlessly with legacy accounting and ACH systems is too resource-intensive. There are also risks to the customer experience: if the integration isn't smooth, the end user (whether a merchant or consumer) experiences an inconsistent transaction. You can't have a system where a customer receives an ‘instant’ confirmation, yet the merchant’s internal reporting doesn't show the funds for 24 hours. That’s bound to increase support ticket requests and lose you trust. 

That’s why it’s so valuable to partner with a trusted payments processor that can manage, integrate, and optimise several payment rails through a single API. In turn, businesses won’t have to worry about which rail a payment leverages and can focus on delivering a seamless customer experience. 

Finally, we have to talk about security. In an instant environment, fraud mitigation must also be instant. You can't wait for a daily batch report to flag a suspicious transaction, and the industry is moving toward real-time collaboration. New regulations, like the Nacha rules and the FedDetect suite, are incentivising banks to collaborate more closely and in real time to stop fraudulent payments.   

With transaction patterns evolving toward everyday retail use over legacy ACH batches, how should fintechs integrate FedNow for high-frequency, secure merchant payouts?

For fintechs and merchants, the shift to FedNow for high-frequency payouts is ultimately about tighter cash flow, fewer support tickets, and a clearer view of money movement in real-time. We’re talking about a transition from scheduled, batch processing (with ACH) to real-time, event-driven payments (with FedNow), based on retail patterns. Instead of waiting for a daily file, fintechs can trigger individual payouts as soon as a sale clears. To achieve a seamless event-driven payment flow, fintechs must change their approach to tech and strategy. 

As FedNow transactions are final and irrevocable, real-time account verification and velocity controls must be a prerequisite. While with ACH, a typo might trigger a Notice of Change or a return, there is no ‘undo’ button with instant payments. Fintechs need to prevent fraudulent or erroneous transfers in milliseconds, before the funds even leave the ecosystem.   

Fortunately, AI-powered tools and velocity controls have proven quite effective in analysing multiple data points to detect and block fraudulent patterns as they appear. We’ve seen this reduce fraud losses by up to 70%. These tools also help reduce false positives, helping businesses block bad actors without slowing legitimate customers.   

We’re seeing some of the most effective, strategic integrations through Embedded Finance. By implementing instant payment rails directly into the merchant’s primary workflow, fintechs can become real-time financial hubs. The system manages the merchant ledger in real time, providing businesses with complete money movement visibility. 

In a cross-border context where stablecoins are leveraged for international reach, what are the integration and compliance requirements for a two-rail system with FedNow?

Great question. The way I see it, not only will money movement speed up, it will split into a two-rail system: FedNow will increasingly serve as the domestic backbone for real-time settlement, whereas ACH will continue to handle high-volume, non-urgent flows. At the same time, stablecoins will open global routes, cutting out the known delays and high fees of cross-border payments. 

Following the 2025 GENIUS Act, the first US federal framework for payment stablecoins, the landscape has become incredibly dynamic. By providing federal clarity, the government essentially set the stage for legitimate, institutional stablecoin adoption. To see how quickly adoption grows when policy and governance align on new payment systems, look at Brazil’s Pix, launched in 2020. By 2024, Pix processed 57 billion transactions, a 53% YoY increase, and is now used by over 70% of Brazilians, making it the country’s most-used payment method. 

For a two-rail setup with FedNow and stablecoin, upfront authentication is the primary requirement: as you cannot reverse payments, senders must get the details right the first time. Modern back-office systems now automate this by matching domestic FedNow requests and their corresponding on-chain stablecoin payments to keep the books balanced. 

We also need remediation controls. Businesses still need a way to handle disputes or errors, even if transactions are final, which usually involves ‘reversing’ the payment through a counter-transaction, rather than a technical ‘undo’ of the original payment. 

As instant payments and stablecoins become normalised, regulators will prompt the industry toward real-time controls, analytics, and fund protection as fast as payments and faster than fraudsters. This governance will be crucial, especially in legitimising stablecoin payments. 

What is needed in terms of policy, risk, and regulatory clarity for FedNow to reach an equal footing with established international counterparts? How do you see it evolving in a global environment?

For FedNow to scale as other global instant payment schemes, regulators and operators must prove that faster also means safer, more transparent, and easier to use, especially for governments and large enterprises. The promise is there; now it needs to be proven in production. 

One of the biggest hurdles to widespread adoption is the fear of fraud, which is a legitimate concern, considering fraud losses from online payments alone are forecast to surpass USD 362 billion globally during 2023-2028, with USD 91 billion in 2028 alone. In 2024, nearly 80% of organisations reported attempted or actual payment fraud activity.   

At the same time, there are persistent security- and privacy-related myths that need dispelling. For one, instant doesn't mean less secure. In many cases, the ISO 20022 messaging standard used by FedNow provides more data and transparency than legacy systems and, when coupled with the right controls, it can actually strengthen fraud detection and compliance.   

However, for government agencies and large-scale enterprises, adoption hinges on budget and planning. They must plan for new infrastructure investment years in advance, which is why we’re seeing a phased, use-case-by-use-case migration rather than a full revamp. 

Another thing to consider is that in many successful instant payments systems abroad, users can send money to a phone number or an alias. In the US, we are still largely tethered to routing and account numbers. Moving toward a more alias-friendly environment would be a significant win, making it easy to use for all. 

The goal for 2026 and beyond is for a merchant in Chicago to receive payment from a customer in London as easily as if they were across the street. This requires a unified regulatory framework that treats instant domestic payments and cross-border stablecoin transfers with the same level of institutional rigour. 

About the author

Jeanette Mbungo is Chief Operating Officer at CSG Forte, responsible for customer success, risk management, and project delivery. Under her leadership, CSG Forte develops and implements future-forward strategies that drive business growth. Since joining CSG Forte in 2014, Jeanette has been integral to CSG Forte’s customer service and technical support operations, advancing the customer experience and influencing a more seamless project delivery. Jeanette has 15+ years of experience in the payments industry. 

 

About CSG Forte

CSG Forte, backed by the experience of CSG, delivers digital payments solutions that help organisations scale faster and smarter. With CSG Forte, organisations process omnichannel payments across a PCI-compliant digital platform that allows customers to make any payments, via any channel, at any time. Our technology empowers organisations to modernise how customers pay bills, increasing on-time payments and customer satisfaction while using a single low-code, unified digital platform.