You've decided to implement instant payments. Good. You've recognized that 2-3 day ACH is a competitive liability. Now comes the hard part: figuring out which rail to use. Should you go RTP? FedNow? Instant settlement? They're all real-time but they're not the same. They have different bank support, different coverage areas, and different price points. Different operational complexity.
Most fintech teams make the mistake of picking one and hoping for the best. That's how you end up with 40% of your transactions settling instantly and 60% falling back to standard ACH. Your competitors who understand multi-rail routing will have better settlement for every transaction. That's a material advantage.
The Coverage Challenge
Here's the reality: no single payment rail has complete coverage. RTP covers roughly 80% of banks. But that percentage varies by region and bank size. Smaller community banks are slower to adopt. Your customers' bank might not be on RTP yet.
FedNow is newer. Even better final-state coverage, but we're still in adoption ramp. Not every bank is live yet. Traditional ACH handles 100% of banks. But it's slow. So, if you pick RTP and a customer's bank doesn't support it, what happens? You either decline the transaction (bad UX) or fall back to slow ACH (defeats the purpose).
The answer is intelligent routing. Not every transaction should go through the same rail. You need logic that says: "For this corridor, use RTP. For this one, use FedNow. For this bank, fall back to standard ACH." This is exactly what Sila’s ACHNow product provides.
This is what multi-rail routing does. It maximizes your coverage and settlement speed simultaneously.
How Multi-Rail Orchestration Works
The best systems use routing logic that considers:
Destination bank and its instant payment capabilities. Is the receiving bank on RTP? FedNow? Neither? Transaction amount. Some banks have limits on what can go through each rail. Time of day. Some rails have better throughput at certain times. Transaction type. Some rails handle certain transaction types better than others. Historical success rates. Over time, the system learns which rails work best for which corridors.
Given these inputs, the routing logic says: "Send this transaction to RTP first. If it fails, try FedNow. If that fails, send it through same-day or standard ACH." The user doesn't know any of this. They just see their payment settle in seconds most of the time, and in a few hours if their bank isn't on the instant rails yet.
40% vs 100%
Here's a concrete example:
Company A picks RTP. 80% of their transactions go through RTP and settle instantly. 20% fall back to standard ACH and take 2-3 days.
Company B uses multi-rail routing. 85% go through RTP or FedNow and settle instantly. Another 10% go through Instant Settlement and settle in hours. Only 5% fall back to same-day ACH due to edge cases.
Company A's user experience: mostly good, sometimes bad.
Company B's user experience: almost always good.
Which do users prefer? Which do users trust more? Which gets better completion rates?
It's not even close.
Building Vs. Buying
The natural question: should we build this in-house? Technically, yes. You can write routing logic. You can integrate with multiple rails. You can monitor each rail's performance and adjust. But here's what most teams underestimate: this isn't a one-time build. Bank coverage changes. Rail capabilities change. New rails emerge. Your routing logic needs constant maintenance. You're burning engineering resources on routing infrastructure instead of your core product. And you're always playing catch-up to banks' infrastructure changes.
The smarter play for most fintech teams is to use a platform that's already solved multi-rail routing, like Sila’s ACHNow solution. We've done the work with the banks. We handle the routing logic. You integrate once and get the benefit of our multi-rail expertise.
The Competitive Timeline
Here's the urgency: every quarter that goes by without multi-rail routing, you're at a settlement disadvantage to competitors who have it. If you pick one rail today and commit to it, you're betting that the market will consolidate around that rail. It might not. You could end up with a routing problem that's expensive and painful to fix.
Multi-rail routing isn't optional in 2026. It's the baseline. The question is whether you build it or buy it. Choose fast and start reaping the benefits in your completion rates and user trust.