Sierra (sierra.ai) is an enterprise conversational AI platform, an "AI Agent OS" that powers customer service agents across both chat and voice. It is used by large enterprises like Rocket Mortgage, SoFi, and Gap to handle high-volume customer interactions with autonomous AI.
Sierra is also one of the few conversational AI platforms with a genuine native payment capability. It is the first Level 1 PCI-compliant conversational AI platform, verified on the Visa Global Service Provider Registry. Its agents can securely capture card data and route it to your existing payment processor, keeping the AI agent out of PCI scope.
So unlike many AI voice and chat platforms, Sierra can take payments. This guide covers what Sierra's native payments give you, and when a dedicated multi-PSP payment layer like Shuttle is the better fit, whether alongside Sierra or in place of its native flow.
If you run multiple gateways, operate under enterprise PSP mandates, or need one payment integration that works the same across every voice and chat agent you deploy, this is for you.
Sierra's Native Payments: What You Get
Sierra's payment capability is strong and worth taking seriously. The core pieces:
Level 1 PCI compliance. Sierra is the first conversational AI platform certified at PCI DSS Level 1 and listed on the Visa Global Service Provider Registry. That is the highest tier of PCI DSS validation.
PSP-neutral capture. Sierra securely captures card data and routes it to the merchant's existing payment processor or gateway. It does not lock you to a single PSP and does not force you onto a particular provider.
Voice and chat. Keypad (DTMF) capture handles payments over voice, and secure embedded forms handle payments in chat sessions.
Agent kept out of scope. The card data never enters the conversational model, which keeps the AI agent itself outside your cardholder data environment.
Flexible payment types. Sierra's flow supports one-off charges, payment plans, bill-pay, and ACH.
For an enterprise standardised on Sierra for customer service, native payments inside the same platform is a clean, well-engineered option. The question is not whether Sierra can take payments. It is whether a single-platform payment flow fits how your payments actually need to work.
When You Need a Dedicated Payment Layer
Native payments are ideal when your stack is consolidated on one vendor. A dedicated payment layer like Shuttle earns its place when payments span more variables than a single platform is built to manage:
Multi-PSP breadth. You process across several gateways and want a single integration that reaches all of them, not a flow tied to one connected processor.
Bring your own gateway. You have negotiated rates or a specific acquirer relationship and want to keep it, with explicit BYO-gateway support.
Per-client and per-tenant routing. Agencies, BPOs, and contact centres run payments on behalf of many end clients, each with their own PSP. You need to route each tenant's transactions to that tenant's gateway.
Enterprise PSP mandates. Large organisations are often required to settle through a mandated processor (Worldpay, Adyen, a regional acquirer). A neutral layer routes to whatever the mandate requires.
Cross-platform consistency. You run Sierra plus other voice or chat agents, or you expect to change agent platforms over time. A dedicated layer keeps one payment integration that works the same regardless of the agent stack on top.
If any of those describe you, a multi-PSP payment layer either complements Sierra or replaces its native flow, depending on how you want to own the payment relationship.
How Shuttle Works With Sierra Today
Be clear about the model first, because it determines whether Shuttle is a fit:
There is no native Sierra integration today. Shuttle's voice payment capture runs on Twilio Pay (Shuttle is Twilio's preferred payments partner). You invoke that Twilio-based setup; you do not install a Shuttle app inside Sierra.
You need to be a Twilio customer to use voice capture with Shuttle.
You need technical resource to implement it. Shuttle ships ready-made interfaces for payment links and the PCI-compliant capture, IVR and APIs for voice, but you build the agent-side interface for your own Sierra workflow, because every agent stack is different. There is no pre-built Shuttle widget for Sierra.
A native Sierra integration is possible as a paid project. If you want a deeper, platform-specific build, Shuttle can deliver one at a project cost.
Carrier-agnostic is on the roadmap. A version that removes the Twilio requirement lands later in 2026; today, Twilio is the live path for voice.
If you have the technical resource and are (or can be) a Twilio customer, the flow works like this:
The agent runs the conversation. Your Sierra agent handles the customer interaction exactly as it does today.
The agent triggers Shuttle at the payment moment. When it is time to collect payment, the agent hands off to Shuttle from the interface you build against Shuttle's APIs.
Shuttle captures the card in isolation. Over voice, the card is captured in a secure, PCI DSS Level 1 call via Twilio Pay: the customer keys their card in on the keypad and the digits are captured inside Shuttle's certified environment, so neither the agent nor any recording is exposed to raw card data.
Shuttle processes and routes to your gateway. Shuttle tokenises the card and routes the transaction to whichever of your connected gateways applies for that customer, currency, or client.
The result returns to the agent. Shuttle passes a clean success or failure result back so the agent can confirm the outcome.
The agent never touches card data, and the payment logic lives in one place across every channel. One honest caveat: the secure capture at the point of payment is what's live now via Twilio Pay. Shuttle being present for the entire Sierra conversation is not yet turnkey. Returning the caller to the same agent and call after payment works today: you program the return route in your Twilio flow and pass a conversation ID, so the agent resumes with context. That fuller call control is where the carrier-agnostic version, landing later in 2026, is headed.
Multi-PSP Support
Shuttle connects to 30+ payment gateways through one integration, including Stripe, Adyen, Worldpay, Checkout.com, Braintree, Square, and Mollie. That breadth is what makes per-client and mandate-driven payments practical:
Per-tenant gateway configuration. Map each client, brand, or business unit to its own gateway and credentials.
One integration, many processors. Add or switch gateways without re-integrating your agents. Switching gateways is configuration, not a re-integration.
Routing rules. Route transactions by currency, region, or card type to the right processor.
Failover. Fall back to a secondary gateway if a primary processor is unavailable.
One voice caveat: a few gateways (for example Braintree) don't permit raw card data to be passed to them, so they don't work for voice capture, though they do work for payment links.
PCI Compliance
Shuttle is a PCI DSS Level 1 certified Service Provider. When Shuttle captures the card, the cardholder data flows through Shuttle's certified environment, not yours and not the agent's.
That shrinks your PCI scope. Because raw card data never lands in your systems, most integrations qualify for the lighter SAQ-A assessment rather than the far heavier SAQ-D you would face if card data passed through your own infrastructure. Your agent platform, your CRM, and your call recordings stay outside the cardholder data environment.
Beyond Voice: Payment Links
Not every payment needs to complete in the live conversation. From the same Shuttle integration, an agent can send an SMS or email payment link that opens a hosted, PCI-compliant checkout page, including mid-call to a caller still on the line. The customer pays on their own device, and the result still routes to your chosen gateway and reports back. Links are the most turnkey part of Shuttle and work even with gateways that don't support voice capture. This is useful when a caller prefers to pay later, needs to switch cards, or wants a written record of the transaction.
Use Cases
Outbound Sales
An outbound Sierra agent closes a sale and collects payment in the same call, routing to the gateway tied to that product line or region.
Bill-Pay and Collections
Agents take bill payments and set up payment plans for overdue balances, with secure card capture and ACH support, ideal for BPOs collecting on behalf of multiple creditors.
Bookings and Deposits
Capture deposits to confirm appointments, reservations, or bookings, with the balance collected later via an SMS payment link.
Customer Support Payments
Support agents resolve an issue and take payment for an upgrade, renewal, or add-on without transferring the customer to a separate line.
FAQ
Does Sierra process payments natively? Yes. Sierra is the first Level 1 PCI-compliant conversational AI platform, listed on the Visa Global Service Provider Registry. It securely captures card data and routes it to your existing payment processor, keeping the agent out of PCI scope.
Why use Shuttle if Sierra has native payments? Sierra's native flow is excellent for a consolidated single-vendor setup. Shuttle fits when you need breadth across 30+ gateways, explicit BYO-gateway support, per-client or per-tenant routing, or one payment integration that works the same across Sierra and any other agent platform you run.
Does Shuttle have a native Sierra integration? Not today. Shuttle's voice capture runs on Twilio Pay (Shuttle is Twilio's preferred payments partner), and you invoke that setup rather than installing a Shuttle app in Sierra. You need to be a Twilio customer and to build the agent-side interface for your workflow. Shuttle can build a native Sierra integration as a paid project, and a carrier-agnostic version is on the roadmap for later in 2026.
Does this require Twilio? Yes, today, for voice. The secure card capture runs via Twilio Pay, where Shuttle is the certified payment connector, so voice capture needs you to be a Twilio customer. Payment links do not require Twilio. The carrier-agnostic version that removes the Twilio requirement is on the roadmap for later in 2026.
Which payment gateways does Shuttle support? Shuttle connects to 30+ gateways, including Stripe, Adyen, Worldpay, Checkout.com, Braintree, Square, and Mollie, through a single integration. Switching gateways is configuration, not a re-integration. A few gateways (for example Braintree) don't work for voice capture but do work for links.
Can I build payment capture into my Sierra agents myself? You can, but building and maintaining a PCI Level 1 capture flow and multi-gateway routing is significant work. Shuttle gives you that as one integration so your team focuses on the agent experience, not payment compliance.
Does this work for outbound calls? Yes. Shuttle captures payments on both inbound and outbound calls via the secure Twilio Pay capture, and can send SMS or email payment links when a caller prefers to pay on their own device.
Related Reading
The Payment Layer for AI Agents: how a dedicated payment layer sits beneath any agent stack.
AI Voice Agent PCI Payments: keeping AI voice agents out of PCI scope.
Voice Payments: how secure payment capture works over voice channels.
Parloa Payments: adding payment capture to Parloa's AI agents.
ElevenLabs Payments: native Stripe payments versus a multi-PSP layer.
Add Payments to Your Sierra Agents
Shuttle gives a Sierra operation PCI Level 1 payment capture across 30+ gateways, on Twilio today, for $0.20 per successful transaction on voice with no setup, monthly, or per-seat fees. Payment links are currently free.
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