“Every few weeks—usually at the start of a new month—the Placed Order and Fulfilled Order metrics stop tracking, and no new orders get recorded in Klaviyo.”
This exact scenario plays out across thousands of WooCommerce stores. One week everything works. The next week, orders complete in WooCommerce but Klaviyo shows nothing. Revenue dashboards go dark. Abandoned cart flows break because Started Checkout never fires.
You re-integrate. It works again. A few weeks later, it breaks again. The cycle repeats.
The Klaviyo WooCommerce integration is fragile by design. It relies on client-side JavaScript, webhooks, and API calls that fail silently whenever caching plugins, security software, or checkout customizations interfere.
The Five Ways Klaviyo WooCommerce Integration Breaks
After analyzing community forums and Klaviyo’s own troubleshooting documentation, the failure patterns are consistent:
1. Caching Plugins Block API Requests
Klaviyo explicitly warns: “If you have active caching plugins or redirect plugins in WordPress, these can interfere with Klaviyo’s integration and cause connection issues.”
WP Rocket, W3 Total Cache, WP Fastest Cache, LiteSpeed—any caching plugin can break the integration. The plugin caches JavaScript or blocks API calls, and Klaviyo never receives the order data.
The recommended fix—disable caching during integration setup—doesn’t prevent the issue from recurring when cache rules change or plugins update.
2. Single-Page Checkout Bypasses Event Tracking
If you’re using CartFlows, FunnelKit, or any single-page checkout, you’ve likely noticed Started Checkout events don’t track.
Klaviyo tracks Started Checkout when customers move from page one (email and address) to page two (payment). Single-page checkouts eliminate that page transition, so the event never fires.
Klaviyo’s official guidance: change to a multi-step checkout, or implement custom API calls. Neither is a realistic fix for stores that chose single-page checkout deliberately.
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3. Security Software Rate-Limits Webhooks
Sucuri, Cloudflare, Wordfence—any security plugin or CDN can block Klaviyo’s webhook requests. Klaviyo’s documentation notes: “Security measures may inadvertently block Klaviyo from communicating with your store or rate limit the speed and amount of data that can be synced.”
The problem: Klaviyo uses dynamic IPs, so you can’t whitelist by IP address. You must whitelist their user agent (Klaviyo/1.0), which requires understanding your security software’s configuration—something most store owners can’t do.
4. Order Status Requirements
Here’s a silent failure mode: WooCommerce orders must reach “processing” status to trigger a Placed Order event in Klaviyo.
Orders with status pending, on-hold, awaiting-payment, or custom statuses never sync. If your payment gateway holds orders in pending status, or you use custom order workflows, Klaviyo never sees the conversion.
Placed Order shows in WooCommerce. Revenue stays at zero in Klaviyo. No error message tells you why.
5. WooCommerce HPOS Migration
WooCommerce’s High Performance Order Storage (HPOS) migration is breaking integrations across the ecosystem. While Klaviyo claims HPOS compatibility, stores migrating to the new order storage architecture are reporting sync failures.
The migration changes how order data is stored and accessed. Any integration relying on the old database structure—including cached API configurations—can fail silently.
Why Re-Integrating Only Temporarily Fixes It
The standard advice: disconnect the integration and reconnect. This works because it forces fresh API credentials, clears cached configurations, and re-establishes webhook connections.
But it doesn’t fix the underlying cause.
The Klaviyo WooCommerce plugin relies on a fragile chain:
- Browser loads klaviyo.js script (blocked by some ad blockers)
- JavaScript tracks customer activity (blocked by caching or JS optimization)
- Webhook fires when order status changes (blocked by security software)
- API receives and processes data (rate-limited by firewalls)
Any link in this chain can break without warning. The integration has no built-in monitoring to tell you when events stop flowing. You discover it days or weeks later when you notice revenue discrepancies.
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The Server-Side Alternative
The Klaviyo integration breaks because it depends on client-side JavaScript and webhook reliability. Server-side tracking eliminates both dependencies.
Server-side tracking fires events directly from your WordPress server when WooCommerce hooks execute. When an order reaches processing status, the woocommerce_payment_complete hook fires, and your server sends the event to Klaviyo immediately.
No browser JavaScript. No webhooks. No caching conflicts. No security rate-limiting.
The event fires from PHP on your server—the same environment WooCommerce uses to process the order. If the order completes, the tracking event fires. There’s no fragile chain to break.
What Server-Side Klaviyo Tracking Looks Like
Transmute Engine™ routes WooCommerce events to Klaviyo server-side. The architecture bypasses every failure point in the native integration:
- Caching plugins: PHP events aren’t cached—they fire in real-time from WooCommerce hooks
- Single-page checkout: Events trigger on hook execution, not page transitions
- Security software: Server-to-server API calls bypass client-side security restrictions
- Order status: You control which hooks trigger events, not Klaviyo’s rigid status requirements
- HPOS migration: Hooks fire regardless of underlying storage architecture
The same principle applies to every marketing platform. GA4, Facebook CAPI, Google Ads, BigQuery—all destinations receive events directly from your server without client-side dependencies.
Key Takeaways
- Klaviyo WooCommerce integration breaks every few weeks due to caching plugins, security software, single-page checkouts, and webhook failures
- Re-integrating temporarily fixes it but doesn’t address the underlying fragility
- Orders must reach “processing” status to trigger Placed Order events—custom workflows break silently
- Single-page checkout bypasses Started Checkout tracking because Klaviyo expects multi-page transitions
- Server-side tracking from WooCommerce hooks bypasses all client-side failure points—events fire when orders complete, regardless of browser or webhook status
The most common causes are: caching plugins blocking API requests, WooCommerce API keys expiring or resetting, security plugins rate-limiting Klaviyo webhooks, or plugin updates breaking the integration. Re-integrating temporarily fixes it until the next conflict occurs.
Klaviyo tracks Started Checkout when customers move from page one (email/address entry) to page two (payment). Single-page checkouts bypass this step, so the event never fires. You need a multi-step checkout or custom API implementation.
Klaviyo only records Placed Order when WooCommerce order status reaches ‘processing’. Orders with status pending, on-hold, or custom statuses won’t trigger the event. Also check that webhooks are functioning and no caching plugin is blocking the API call.
Server-side tracking from your WordPress server bypasses all client-side issues. Events fire directly from WooCommerce hooks when orders complete—no browser JavaScript, no webhooks to fail, no caching conflicts. Platforms like Transmute Engine route Klaviyo events server-side.
Stop re-integrating every month. Learn how server-side tracking fixes Klaviyo permanently at seresa.io.
