Custom Objects: Klaviyo’s Biggest Backend Upgrade Yet

26 February 2026 Nick

Klaviyo’s Custom Objects are the missing link for smarter data

Among Klaviyo’s many recent feature releases, one we’re particularly excited about is the official launch of Custom Objects. This update gives marketers a powerful new way to store, manage and activate structured data within Klaviyo.

Until now, storing complex data like product bundles, warranties, subscriptions or accounts often meant bloated profiles, messy workarounds or external systems.

With Custom Objects, we can now:

Store structured data for any use case such as subscriptions, appointments, bookings, applications and more.
Build advanced relationships between custom objects and customer profiles.
Reference and use custom object data for more precise segmentation, template personalisation and flow triggering.

This means you can show dynamic event or appointment details in emails, use subscription data to power lifecycle flows or capture and act on detailed customer preferences all natively in Klaviyo.

Developers can push Custom Objects into Klaviyo through the API, giving marketers immediate access to use that data in flows and templates without relying on engineers each time.

In effect, this release brings Klaviyo closer to a full CRM + CDP hybrid, enabling smarter retention strategies and more personalised customer journeys.

Learn more here: