One Link, Many Channels
A payment link is just a URL. It opens a branded checkout page where your customer picks their payment method, enters their details, and pays. The whole interaction takes under 60 seconds.
The link itself doesn't change. What changes is how you deliver it.
Send the same link by email, text it to a mobile number, share it on WhatsApp, print it as a QR code on an invoice, or read it out over the phone. The customer lands on the same checkout page regardless of how they got there.
This is the real advantage. Different customers respond to different channels. A B2B client checking email at their desk behaves differently from a homeowner who just had their boiler fixed. A guest checking out of a hotel is not the same as a debtor receiving a collections notice.
The businesses that collect fastest are the ones matching the payment channel to the customer, not forcing every customer through the same funnel.
Email: The Default Starting Point
Email is where most businesses start with payment links, and for good reason. It's familiar, it's free to send, and it works well for anything invoice-related.
The typical flow: you generate an invoice, include a "Pay Now" button or link in the email, and the client clicks through to a branded checkout page. No PDF downloads. No manual bank transfers. No reference numbers to copy.
Best for:
B2B clients and professional services
Recurring billing and subscription renewals
Invoice follow-ups where you already have an email thread
Larger transactions where the customer expects documentation
Strengths: No character limits, so you can include full context around the payment. Works across every device. Easy to automate from your invoicing or CRM system. Provides a natural paper trail.
Weaknesses: Emails get buried. Your payment link is competing with 80 other unread messages in your client's inbox. Average email open rates sit around 20-25% for transactional messages. If your client's accounts payable person is on holiday, that email sits untouched until they get back.
Email works. But it's slow. If speed matters, you need a second channel.
SMS: Highest Open Rates, Fastest Response
SMS open rates sit around 98%. Most text messages are read within 3 minutes of delivery. Compare that to email's 20-25% open rate and you can see why SMS payment links convert significantly faster.
The format is simple: a short message with context and a link. "Hi Sarah, your invoice #1042 for £450 is ready. Pay here: [link]." The customer taps the link, lands on the checkout page, and pays.
Best for:
Payment reminders and overdue invoices
Time-sensitive collections (field service, deliveries, appointments)
Younger demographics who live on their phones
Customers you don't have an email relationship with
Strengths: Near-instant delivery. Near-universal open rates. Works on every mobile phone, including older handsets without WhatsApp. Short and direct, which suits payment prompts.
Weaknesses: Character limits mean you can't include much context. SMS costs money per message (typically 3-5p per send in the UK). Some customers are wary of links in text messages due to smishing scams, so branding and trust signals on the checkout page matter. You also need the customer's mobile number, which isn't always available for B2B contacts.
Tip: Use a URL shortener or branded short domain so the link looks trustworthy. A link from "pay.yourbrand.com" converts better than a generic shortened URL.
WhatsApp: Rich Messaging With Global Reach
WhatsApp has over 2 billion active users worldwide. In markets like India, Brazil, and large parts of Europe, it's the default messaging app. Even in the UK, WhatsApp is the most-used messaging platform after standard SMS.
Sending a payment link via WhatsApp gives you more than just delivery. You get read receipts, rich formatting, the ability to include images or branding, and a conversational thread the customer can reply to with questions before they pay.
Best for:
International customers (especially in markets where WhatsApp dominates)
Hospitality and personal services (salons, private healthcare, event management)
Ongoing client relationships where you already chat on WhatsApp
Situations where the customer might have questions before paying
Strengths: Higher engagement than SMS in many markets. Rich message formatting. Two-way conversation. Read receipts so you know the message was seen. Free to send for most business use cases through WhatsApp Business API.
Weaknesses: Requires the customer to have WhatsApp installed. You need their phone number and opt-in consent (WhatsApp Business API rules require this). Setting up the WhatsApp Business API takes more effort than sending an SMS. Not ideal for formal B2B communications where email is expected.
WhatsApp works especially well as a follow-up channel. Send the invoice by email. If it's not paid in a week, send a WhatsApp message with the same link. The conversational format makes it feel like a friendly nudge rather than a formal demand.
QR Codes: Bridging Physical and Digital
A QR code is just a payment link encoded as an image. The customer scans it with their phone camera and lands on the checkout page. Same link, different delivery method.
What makes QR codes powerful is that they work in physical contexts where you can't send a digital message. Print one on a paper invoice. Display one at a reception desk. Put one on a door hanger after a property viewing. Include one in product packaging.
Best for:
Paper invoices and statements (accounting firms, utilities, property management)
Events, conferences, and ticketing
Retail and hospitality (countertop payments, table payments)
Field service (leave a QR code after a job for the customer to pay at their convenience)
Property viewings and letting agents
Strengths: Works in physical spaces where digital channels can't reach. No need for the customer's contact details. The customer initiates the payment at their own pace. Easy to generate and cheap to print.
Weaknesses: Requires the customer to have a smartphone with a camera. Older demographics may not be comfortable scanning QR codes (though adoption has increased significantly since COVID). You can't track delivery the way you can with SMS or email, so you don't know if the customer has seen the code.
Tip: Always include the payment amount and a brief description next to the QR code. "Scan to pay £320 for your March service visit" gives the customer confidence before they scan.
Voice: Phone-Based Payment Capture
Not every customer is sitting at a screen. Some are on the phone with your team right now, ready to pay, and the fastest path is to take the payment during the call.
Voice payments work through DTMF (where the customer types their card number on the phone keypad) or through AI voice agents that guide the customer through payment verbally. Either way, the call stays PCI-compliant because the payment data never touches your systems.
Best for:
Contact centres and customer service teams
Debt collection and payment plans
Insurance renewals and claims
Older demographics who prefer phone over digital
High-value transactions where the customer wants to speak to someone
Strengths: Captures payment at the moment of intent. No waiting for an email to be opened or a link to be clicked. Personal interaction builds trust, especially for larger amounts. Works for customers who don't use smartphones or aren't comfortable with digital payments.
Weaknesses: Requires a phone interaction, so it's not scalable the same way automated channels are. PCI compliance for voice is more complex than for payment links. Costs more per transaction than self-service channels.
Shuttle's Voice Checkout handles this at $0.20 per transaction through the Twilio Marketplace. It works with existing phone systems, supports AI voice agents, and keeps your contact centre out of PCI scope entirely.
Choosing the Right Channel for Your Customer
The best channel depends on who your customer is, what they owe, and how urgently you need to collect.
Customer Type | Primary Channel | Secondary Channel | When to Use |
|---|---|---|---|
B2B clients on account | Phone (voice) | Invoice payments, recurring billing | |
Consumer service customers | SMS | Post-service payments, reminders | |
International customers | Cross-border collections | ||
Walk-in or in-person customers | QR code | SMS (if you have their number) | Retail, hospitality, events |
Overdue accounts | SMS | Phone (voice) | Collections, payment plan setup |
Older demographics | Phone (voice) | Insurance, utilities, property | |
Field service customers | SMS or QR code | After job completion |
The key insight: you don't have to pick one channel. The businesses with the highest collection rates use multiple channels for the same payment, starting with the most convenient and escalating to the most direct.
Multi-Channel Sequences: The Escalation Pattern
The most effective approach to payment collection isn't picking the right channel. It's using the right sequence of channels.
Here's a pattern that works across industries:
Day 0: Send the invoice by email with a payment link. This is the standard starting point. Many customers will pay within 48 hours.
Day 7: If unpaid, send an SMS reminder with the same payment link. "Your invoice #1042 for £450 is still outstanding. Pay here: [link]." Short, direct, and arrives on their phone screen.
Day 14: If still unpaid, follow up on WhatsApp. The conversational format works well here because you can ask if there's an issue. "Hi, just checking you received the invoice for your March service. Here's the payment link if you need it: [link]. Let me know if you have any questions."
Day 21: Try a different time of day or combine channels. Resend the email with an updated subject line. Send another SMS. Sometimes the issue is simply timing.
Day 30+: Move to voice. A phone call with the option to pay during the call. This is where Voice Checkout becomes valuable. The customer is on the phone, the agent can address any concerns, and the payment can be captured right there. No "I'll pay it when I get to my computer" and another two weeks of waiting.
This sequence works because each channel is progressively more personal and harder to ignore. Email is passive. SMS is direct. WhatsApp is conversational. Voice is personal.
The same payment link works across all of these channels. You generate it once and deliver it however makes sense. Shuttle's Payment Layer handles the link generation, PSP routing, and checkout page. You focus on choosing the right channel and timing.
FAQ
Do I need separate providers for each channel?
No. A payment link is a URL that works everywhere. You generate one link and send it via whatever channel suits your customer. Shuttle creates branded payment links that work across email, SMS, WhatsApp, QR codes, and web embeds through a single integration. Voice payments use a separate product (Voice Checkout), but it's the same platform underneath.
What about GDPR and consent?
You need a lawful basis for contacting someone on each channel. For email, legitimate interest or contractual necessity usually covers payment collection communications. For SMS and WhatsApp, you should have explicit consent to message the customer on that channel, and they must be able to opt out. WhatsApp Business API has its own opt-in requirements. For voice, standard telephone regulations apply. None of this is unique to payment links. The same rules apply to any business communication on these channels.
Can I track which channel converts best?
Yes. Use UTM parameters or unique link identifiers per channel. If you send the same payment via email and SMS, use a slightly different URL parameter for each so you can see which one the customer used. Over time, this data tells you which channels work best for which customer segments. Most businesses find SMS converts fastest, email converts the most total volume, and voice captures the highest average transaction value.
How much does each channel cost?
The payment link itself is the same price regardless of channel. With Shuttle, Links Checkout is $49 per user per month. On top of that, each delivery channel has its own cost: email is effectively free if you have an email provider, SMS costs 3-5p per message in the UK, WhatsApp Business API messages are priced per conversation (varies by country), QR codes cost nothing beyond printing, and Voice Checkout is $0.20 per transaction through the Twilio Marketplace.
Can I automate multi-channel sequences?
Yes. Most CRM and invoicing platforms support automated email reminders. SMS can be triggered through APIs when an invoice hits a certain age. The escalation pattern described above can be fully automated with the right integrations. Shuttle's API lets you generate payment links programmatically, so you can plug them into whatever automation workflow you already use.
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