Klaviyo + WhatsApp API Integration — Complete Guide 2025

Klaviyo is the gold standard for e-commerce email marketing. WA.Expert adds WhatsApp to every Klaviyo flow — so your abandoned cart, post-purchase, and win-back sequences reach customers on WhatsApp where Indian audiences have 94% open rates vs 35% for Klaviyo emails.

Connect Klaviyo + WhatsApp → Talk to an Expert

E-commerce

Klaviyo + WhatsApp for Shopify/WooCommerce brands

94% vs 35%

WhatsApp open rate vs Klaviyo email for Indian audiences

All flows

Abandoned cart, post-purchase, win-back — WhatsApp in every flow

150K+ brands

Klaviyo serves the world's top e-commerce brands

What You Can Automate

Top use cases for Klaviyo + WhatsApp API

Klaviyo is the leading e-commerce email and SMS marketing platform used by 150,000+ brands globally. WA.Expert adds WhatsApp as a third channel in Klaviyo flows — abandoned cart, post-purchase, win-back — with 94% open rates vs Klaviyo email's 35%.

🛒

Abandoned cart flow → WhatsApp

Klaviyo abandoned cart flow adds WhatsApp step — fires when email doesn't convert.

📦

Post-purchase flow → WhatsApp

Klaviyo post-purchase sequence adds WhatsApp for review request and reorder nudge.

♻️

Win-back flow → WhatsApp

Klaviyo win-back sequence adds WhatsApp to re-engage lapsed customers who ignored emails.

🔔

Back in stock alert → WhatsApp

Klaviyo back-in-stock trigger fires WhatsApp to waitlisted customers before email.

Trigger → Action

How Klaviyo events trigger WhatsApp messages

Klaviyo trigger	WhatsApp action (WA.Expert)	Business impact
Checkout Started (email not opened 4hr)	WhatsApp abandoned cart recovery	55% additional recovery
Order placed (post-purchase D3)	WhatsApp review request	+600% review rate
Customer hasn't ordered in 90 days	WhatsApp win-back (email failed)	15-22% lapsed recovery
Back in stock event	WhatsApp before email to opted-in waitlist	High-intent conversion
Subscription renewal D-7	WhatsApp reminder to update card	Reduces involuntary churn

Setup Guide

How to connect Klaviyo to WhatsApp API

Use Klaviyo webhook action in flows

In Klaviyo Flow editor: add a Webhook action step. Set URL to WA.Expert API endpoint. Configure the JSON payload with person phone and product/order variables. This fires WA.Expert within the Klaviyo flow.

Map Klaviyo profile properties to WhatsApp

Klaviyo profile properties (first_name, phone_number, $email) are available as variables in the webhook payload. Map phone_number to WA.Expert "to" field. Map product name, order total, cart recovery URL to template variables.

Position WhatsApp steps strategically in flows

Best practice: email → wait 4 hours → if not opened → WhatsApp. This ensures WhatsApp only fires for contacts who didn't open the email — avoiding double-messaging engaged email subscribers. For back-in-stock and time-sensitive alerts, WhatsApp fires first.

Handle opted-in vs non-opted-in contacts

Only send marketing WhatsApp to contacts who explicitly opted in to WhatsApp. Create a Klaviyo profile property "whatsapp_opted_in" and add a condition in your flow: only proceed to WhatsApp step if this property is True.

Set up win-back with WhatsApp supplement

In Klaviyo win-back flow: after 3 unanswered emails, add a WhatsApp step. Lapsed customers who ignored email are often still reachable on WhatsApp. The WhatsApp win-back step typically recovers 15–22% of contacts that email alone couldn't.

Sample Klaviyo → WhatsApp configuration

// Klaviyo Flow Webhook → WA.Expert
// Abandoned Cart flow, 4hr email delay
// Condition: email not opened
// Action: Webhook POST to WA.Expert

{
  "to": "{{ person|lookup:'phone_number' }}",
  "template": "klaviyo_cart_recovery",
  "variables": {
    "name": "{{ person|lookup:'first_name' }}",
    "product": "{{ event.extra.ItemNames.0 }}",
    "cart_url": "{{ event.extra.CheckoutURL }}",
    "total": "{{ event.extra.Value }}"
  }
}

WA.Expert handles WhatsApp API authentication, template approval, and delivery. You pass trigger data from Klaviyo — no WhatsApp API expertise needed.

FAQ

Klaviyo + WhatsApp — common questions

How is WhatsApp different from Klaviyo SMS for Indian audiences?

Klaviyo SMS in India requires an Indian telecom registration and has lower open rates (72%) compared to WhatsApp (94%). WhatsApp also supports rich media (images, buttons, documents) that SMS doesn't. For Indian e-commerce brands targeting consumers, WhatsApp is significantly more effective than SMS as a marketing channel.

Can I add WhatsApp to existing Klaviyo flows without rebuilding them?

Yes — adding a Webhook action step to an existing Klaviyo flow is non-destructive. Simply add the step at the appropriate point in your existing flow (after an email non-open condition, or as a standalone step) and test with a small segment before enabling for all flow recipients.

How do I ensure I only send marketing WhatsApp to opted-in customers?

WhatsApp Business API requires opt-in for marketing messages. In Klaviyo, create a custom profile property "whatsapp_opted_in" = true. Add a Flow Filter or Trigger Filter: only proceed if this property is true. Collect opt-in via checkout checkbox or post-purchase WhatsApp opt-in message.

Can Klaviyo predict which contacts to target with WhatsApp vs email?

Klaviyo's predictive analytics identifies email-unengaged customers. Create a Klaviyo segment of contacts with email open rate below 10% in the last 90 days. This segment is your WhatsApp-first audience — they're reachable on WhatsApp but not on email. Run WhatsApp campaigns to this segment independently of your email flows.

Does this work with Klaviyo's Shopify integration?

Yes — the most common stack is Shopify + Klaviyo + WA.Expert. Shopify order data flows to Klaviyo. Klaviyo triggers flows based on order events. WA.Expert fires WhatsApp at strategic flow points. All three tools connect natively: Shopify → Klaviyo (native), Klaviyo → WA.Expert (webhook).

What Klaviyo plan supports webhook actions in flows?

Klaviyo webhook actions in flows are available on Klaviyo Email plans (not just SMS plans). All Klaviyo paid plans include Flow webhook actions. The free plan (up to 500 contacts) also supports webhook actions — making it possible to start Klaviyo + WA.Expert at zero Klaviyo cost.

Related Integrations

More WhatsApp integration guides

Ready to add WhatsApp to your Klaviyo flows?

Email + WhatsApp = 3× higher engagement. Add WhatsApp steps to abandoned cart, post-purchase, and win-back flows. Reach the customers Klaviyo email can't.

Start Free Trial → Talk to an Expert