When it comes to payments made over the phone, two methods dominate: DTMF and payment links. Both are secure. Both are PCI-compliant. But they solve slightly different problems — and understanding when to use each is key to building a reliable, friction-free payment experience.
In this article, we’ll break down how each method works, what risks they mitigate, and why combining them through Shuttle’s Payment Layer gives your customers the best of both worlds.
What Is DTMF Payment Capture?
DTMF (Dual-Tone Multi-Frequency) is the technology behind the beeps you hear when pressing numbers on a phone keypad. In payment terms, it allows customers to enter their card numbers securely during a call, without ever speaking them aloud.
Each keypress generates a tone, which is captured, masked, and sent directly to a PCI-compliant payment environment — keeping the card details hidden from the agent, call recording, and internal systems.
DTMF is popular in industries like insurance, collections, and utilities because it keeps the customer on the line and maintains conversational flow.
What Is a Payment Link?
A payment link is a secure URL sent via SMS, email, or chat that lets customers complete payment in their browser. The link opens a pre-filled checkout page with all the transaction details already included — amount, reference, merchant ID, and expiry time.
It’s the digital counterpart to voice payments: instead of capturing tones, the customer completes the payment visually. Links are mobile-friendly, fast to issue, and easy to brand.
For customers who prefer not to enter card details over the phone — or when voice capture fails — payment links are the natural fallback.
Security Comparison: DTMF vs Link
Both methods can be fully PCI-compliant when implemented correctly. The difference lies in how they achieve security and where they place the compliance burden.
| Feature | DTMF Payments | Payment Links |
|---|---|---|
| Data exposure | Card tones captured directly by PCI-certified system, never stored in IVR or CRM. | Card data entered on secure hosted checkout, never passes through your systems. |
| Customer experience | Instant, real-time payment while on call. | Asynchronous — customer can pay later via SMS or email. |
| Risk factors | Potential tone interference or keying errors; call quality dependent. | Potential phishing or link-trust issues if poorly branded. |
| Best suited for | Voice IVR and agent-assisted payments. | Digital, chat, or post-call follow-up payments. |
In practice, both methods complement each other. DTMF excels in immediacy; links excel in flexibility.
Compliance and PCI Scope
One of the biggest advantages of using Shuttle is that both DTMF and link transactions pass through the same Payment Layer — a PCI-compliant, multi-processor environment that keeps your infrastructure out of scope entirely.
That means no matter how your customer pays — by phone, SMS, or browser — you maintain the same compliance posture, reporting, and audit trail.
It’s a unified approach to compliance that removes the need for separate systems or certification processes per channel.
Experience and Trust
Security is only part of the story. Trust and ease of use determine whether a customer completes payment at all.
- DTMF: feels private and immediate. The customer stays in control without revealing details aloud.
- Links: feel familiar and transparent. The customer can see the branded checkout and confirm details visually.
Offering both methods signals professionalism and choice — the two pillars of modern customer experience.
When to Use Each
In most enterprise setups, the right answer is not “either/or” — it’s “both.”
- Use DTMF when you want to complete the payment immediately during the call.
- Use Payment Links when a call drops, when the customer requests more time, or when you need a digital record of the transaction.
Shuttle allows you to combine both methods within the same flow, automatically switching between them when needed — ensuring every payment succeeds.
Twilio Integration Made Simple
For teams using Twilio to power IVR and contact-centre experiences, Shuttle’s APIs and Studio webhooks make it simple to integrate both DTMF and link payment options without rewriting code or adding PCI scope.
Your IVR prompts the customer for card entry, Shuttle captures and tokenises it. If that fails, the system triggers a branded payment link automatically — all using the same processor configuration.
It’s one secure workflow, many possible outcomes.
Unified Reporting and Reconciliation
Whether the transaction happens via DTMF or link, Shuttle records everything under the same merchant profile and processor route. That means unified reporting, consistent reconciliation, and cleaner financial data — no manual stitching between channels.
The Verdict: Flexibility Wins
When it comes to secure phone payments, there’s no universal winner between DTMF and link checkout. The best systems — and the best experiences — combine both seamlessly.
DTMF keeps the call in flow. Links keep the customer in control. Shuttle connects them under one compliant, multi-merchant payment layer that scales with every conversation.
Learn more about Shuttle’s IVR & Voice Payments and see how we unify voice and digital checkout into one intelligent experience.
