Klaviyo WhatsApp Integration: How to Run Both Channels

Start with what each channel is structurally good at, not with which one you like. Email is a broadcast channel with unlimited room and a low cost per send. WhatsApp is a conversation channel with a very high read rate and very little room. Those two facts decide almost every routing question later.

• Email in Klaviyo — cheap per send, unlimited length, good for storytelling and segmentation. Best for newsletters, product launches and long lifecycle tracks. Published benchmark band for open rates: 30–40%.
• WhatsApp in Keaz — 90%+ read rate in the published band, short messages, customers can reply. Best for cart recovery, shipping updates, re-order reminders and back-in-stock.
• Both together — on the shared audience, conversion goes from 2.1% to 4.5%. We quote roughly 1.5x rather than the top of that range.
• Cost — email is cheaper per send, WhatsApp is more expensive per message. The fair comparison is cost per additional revenue, not cost per send.

The read- and open-rate figures above are published benchmark bands, not our own measurements; how we calibrate them is described in how the Keaz forecast is calculated. The channel-by-channel numbers are broken down further in our comparison of WhatsApp and email marketing.

One piece of external context matters for DACH stores: according to the German Federal Statistical Office (Destatis, 2026, on Eurostat data), 83% of people aged 16 to 74 in Germany used messenger services such as WhatsApp in the first quarter of 2025, up from 80% a year earlier — while only 59% were active on social networks. The channel your customers already live in is the messenger, not the feed. Source: Statistisches Bundesamt, digital communication in Europe (2026).

Shopify is the required connection; Klaviyo is the optional second one. You find it under Settings → Integrations → Klaviyo, and connecting it changes two things: what Keaz can measure, and what it can target. The step-by-step is in our help centre article on the Klaviyo integration settings.

1. Shopify only. Keaz runs your event-driven WhatsApp flows and tracks CCC — Customer Contact Coverage, the share of your last-12-months Shopify customers you can reach on WhatsApp. Most stores start between 35% and 55% and reach 85%+ within about 60 days.
2. Shopify plus Klaviyo. Your Klaviyo segments become selectable audiences inside Keaz — for newsletters and as a flow's entry segment — so you do not maintain the same list twice. Keaz also starts tracking MCC, Marketing Contact Coverage: the share of your email subscribers you can also reach on WhatsApp. MCC typically starts at 15–30% and lands at 50–70%.

It is worth being precise about what the connection does and does not do. A Klaviyo segment does not fire a WhatsApp message by itself. A flow is still started by an event — a purchase, an abandoned checkout — and the segment decides who that trigger applies to. That separation is what keeps the two channels independent enough to route cleanly.

Two mechanics do the actual list-building, and both use email to grow WhatsApp rather than compete with it. A launch campaign is a one-shot invitation to your existing email list to continue on WhatsApp, with a 90-day cooldown built in so it cannot be repeated into fatigue. An email footer CTA is a persistent WhatsApp opt-in link under every email you already send — it costs nothing extra and compounds quietly. The flows and coverage strategies are listed on the Keaz features overview.

The routing rule is short: intent goes to WhatsApp, breadth and story stay in email. A message that has to arrive within minutes to be worth anything belongs on WhatsApp. A message that needs three images and 400 words belongs in Klaviyo.

1. Newsletter, product story, campaign to the whole list — Klaviyo. Nothing here benefits from a 90%+ read rate at a higher cost per message.
2. Abandoned cart — WhatsApp. Cart recovery is the highest-converting flow at an 18–30% recovery rate, because the decision window is short.
3. Shipping and delivery updates — WhatsApp. These are read, not filed, and they lift repeat purchase rate by 10–15%.
4. Back-in-stock — WhatsApp. This is your highest-intent audience and converts at 25–40%.
5. Re-order reminder — WhatsApp, if you sell consumables. Timed to the customer's own cycle it converts at 12–22%.
6. Winback after 90+ days and review requests — pick one channel per customer, never both. Reactivation runs at 3–7%, and doubling it up does not double the result.

How much each flow is worth depends heavily on your vertical: re-order reminders carry pet, beauty and food stores, while cart recovery carries fashion and home. The per-vertical ranges are on the industries page for WhatsApp marketing benchmarks.

Double-messaging is the one failure mode that makes a two-channel setup worse than a one-channel setup. It annoys the customer, it costs twice, and it makes attribution useless. Four habits prevent it.

1. Write down one owner per trigger. A single sheet with the trigger in one column and the owning channel in the other settles nine out of ten arguments before they happen.
2. Suppress the other channel for shared triggers. If a contact is reachable on WhatsApp and cart recovery is a WhatsApp flow, exclude them from the email version of that flow — not from your newsletter.
3. Respect the cooldowns. A launch campaign carries a 90-day cooldown, and Smart Activation — the re-permissioning run for customers who last ordered more than 12 months ago — is throttled to two runs per year. Both limits exist because list-building messages are the easiest way to burn goodwill.
4. Collect consent per channel. An email opt-in is not a WhatsApp opt-in. Ask separately, document it, and keep it revocable at any time. Which messages you may send to whom follows from the contact's opt-in level — our help centre sets out how subscribing and unsubscribing works.

On the consent point, the principle in European data protection law is that the controller must be able to demonstrate the consent it relies on (Art. 7 GDPR, Regulation (EU) 2016/679, EUR-Lex). In practice the cleanest place to collect a WhatsApp opt-in is the Shopify checkout, separately from the email consent. Our guide to collecting WhatsApp opt-ins walks through each capture point.

This is a summary of principles rather than legal advice — have your own counsel review your implementation.

Most two-channel setups do not fail on strategy. They fail on five avoidable mistakes.

1. Sending the same campaign on both channels. The customer reads it once and is irritated twice, and you paid for both. Pick an owner per trigger instead.
2. Treating an email opt-in as a WhatsApp opt-in. It is not, and it is the mistake with the highest downside on this list.
3. Using WhatsApp for cold reach. WhatsApp earns its higher cost per message on intent-driven flows. Fire it at an unsegmented list and you get the cost without the conversion.
4. Launching flows without measuring coverage. If you do not know your CCC and MCC, you cannot tell whether a weak month was a bad message or a small reachable audience. Both sit in the Audience area, alongside the segments you send to.
5. Planning to replace email. 24% of customers in our own audience split are reachable by email and nowhere else. Cutting email to fund WhatsApp removes a quarter of your reach.

If you are earlier than this and still deciding how WhatsApp fits into your store at all, start with the complete guide to WhatsApp marketing for Shopify and come back to the routing questions afterwards.

Do I need Klaviyo to use Keaz?

No. Shopify is the only required connection, and the event-driven WhatsApp flows run on your shop events alone. Connecting Klaviyo adds MCC tracking and makes your Klaviyo segments available as audiences inside Keaz.

Will I lose email revenue by adding WhatsApp?

That is not what the split shows. 24% of customers are reachable by email only, so email keeps its own audience. WhatsApp adds the 34% who are reachable there and nowhere else, and lifts conversion on the 38% overlap.

Do I have to rebuild my Klaviyo segments in Keaz?

No. Once the integration is connected, your Klaviyo segments appear as selectable audiences for newsletters and as a flow's entry segment, next to the segments you build yourself in Keaz.

Do I need a separate opt-in for WhatsApp?

Yes. Treat WhatsApp consent as its own explicit, documented and revocable opt-in, collected separately from the email consent. This is a summary rather than legal advice — have your own counsel review it.