We’ve all been there: you book a ticket, order food, or make a payment, and then… silence. No confirmation. No reassurance. You start to wonder: Did it even go through? Eventually, a generic SMS trickles in from a random short code. Not exactly confidence-inspiring.

SMS is often unreliable, especially when delivery depends on shaky cellular networks. That’s why Prelude now supports WhatsApp transactional messages giving businesses a faster, branded, and internet-based way to deliver important updates right inside WhatsApp.

What Are WhatsApp Transactional Messages?

Transactional messages aren’t ads or promotions. They’re the critical updates users expect after taking action. Examples include:

• “Your table is confirmed for tonight at 7:00 PM.”

• “Your package has shipped with tracking number: #48291.”

• “Your payment of $42.50 was received successfully.”

On WhatsApp, these messages are sent using approved templates. You design the format with placeholders (e.g., {{1}} for a tracking ID), Meta approves it once, and then you can send it reliably at scale. For secure logins, businesses can also use WhatsApp OTP.

Why Use WhatsApp for Transactional Messaging?

• Speed: Delivery is near-instant, even in regions where SMS verification is slow.

• Trust: Messages come from your verified business account with name and logo.

• Reach: WhatsApp has 2B+ active users and works even where cellular connectivity is weak.

• Security: Every message benefits from WhatsApp’s end-to-end encryption.

Instead of competing with SMS spam, your messages feel personal, secure, and credible.

How to Integrate With Prelude

Getting started is straightforward. Prelude handles the heavy lifting so you can focus on building.

Step 1: Connect Your WhatsApp Account

• Log into the Prelude Dashboard.

• Go to Settings → Integrations → Providers.

• Click Connect with Facebook to open Meta’s Embedded Signup popup.

Step 2: Complete Embedded Signup

• Follow the guided steps to link your WhatsApp Business Account.

• Refer to Prelude’s documentation if you need details.

Step 3: Finalize & Verify

• Click Finish to complete the linking process.

• Once the page reloads, your WhatsApp account and connected phone number will appear in the list of providers.

Step 4: Enable WhatsApp on Routes

• Go to Settings → Routes.

• Enable WhatsApp for the flows where you want to send transactional messages.

From here, sending a message is one simple API call:

curl -X POST https://api.prelude.so/v2/transactional \

  -H "Authorization: Bearer <API_KEY>" \

  -d '{

    "phone_number": "+14155552671",

    "template_id": "template_01jd1xq0cffycayqtdkdbv4d61",

    "variables": {"tracking_id": "#48291"}

  }'

Prelude manages delivery, compliance, retries, and fallbacks (like SMS if WhatsApp fails).

What Does It Cost?

As of July 1, 2025, WhatsApp charges on a per-message basis for all template messages, including transactional updates.

• WhatsApp bills per delivered template message, with rates varying by country.

• Meta offers tiered pricing, so high-volume senders benefit from lower rates.

• With Prelude, you get the same WhatsApp base rates plus orchestration value: we handle template approvals, retries, fallbacks, compliance checks, and analytics. All through one integration.

Approximate Transactional Rates (before volume discounts):

* Based on Prelude pricing, which passes through Meta’s rates with a small service fee for orchestration.

Compared to going directly through Meta, Prelude saves you from managing OTP storage, retries, and session logic. With us, it’s just one API call and your transactional messages land reliably, every time.

Final Thoughts

Silence breaks trust. WhatsApp transactional messages turn uncertainty into confidence.

With Prelude, integration takes minutes and sending is as simple as a single API call. Whether it’s an OTP, a shipping update, or a booking reminder, we’ll help you deliver it securely and at scale.

👉 Start sending with Prelude today
👉 Book a demo to see it in action