Klaviyo Custom Objects: Ecommerce Personalization Guide

Klaviyo Custom Objects ecommerce personalization is now available to every account — not just enterprise. As of October 16, 2026, Custom Objects are generally available across all Klaviyo plans, giving brands a way to attach structured, complex datasets to customer profiles and use that data inside flows, segments, and email content. The short version: if your personalization strategy has been limited to "first name, last order date, and total spent," you now have the tools to go significantly further.

What Are Klaviyo Custom Objects? (The Plain-English Explanation)

Custom Objects are user-defined data schemas that you create inside Klaviyo and attach to customer profiles. Think of them as custom tables in a database — except they live directly on the customer record and are natively accessible from your flows, segments, and email template personalization blocks.

Standard Klaviyo profile properties are flat key-value pairs: loyalty_tier: "Gold", total_orders: 7. They work well for simple data but fall apart when your business tracks anything with internal structure. A subscription box customer doesn't have one product — they have twelve, each with a SKU, a category, a quantity, and a fulfillment date. Before Custom Objects, you either crammed all of that into a single text string (unusable for logic) or kept it in a separate system entirely (not available in Klaviyo).

Custom Objects solve this by letting you define a schema — a named object type with typed fields — and then attach instances of that schema to individual profiles. A SubscriptionBox object might have fields like box_id (string), ship_date (date), contents (list of product objects), and tier (string). Once that object is defined and populated, every field becomes available in flow conditions, segment filters, and email dynamic blocks.

This is the data model change Klaviyo needed for brands running anything more complex than a straightforward transactional store — and it's been available to enterprise accounts since early 2026. The October 16 GA release brings it to everyone.

What You Can Build That Was Impossible Before

The practical unlock Custom Objects provide isn't just "more data" — it's data with structure that Klaviyo's logic engine can actually evaluate. Here's what that enables that was genuinely not possible before:

Trigger flows on specific object field changes. Before Custom Objects, flow triggers were limited to standard Klaviyo events (placed order, started checkout, etc.) and basic profile property changes. Now you can trigger a flow when a customer's loyalty tier field changes from "Silver" to "Gold," or when a subscription object's renewal_date is within 7 days. These are business-logic triggers, not just transactional triggers.

Segment on nested data. Standard segmentation lets you filter on order count, revenue, or product category. Custom Objects let you filter on any field inside your custom schema. "Show me customers whose most recent subscription box contained a product from the skincare category" — previously a data warehouse query, now a native Klaviyo segment.

Personalize email content with structured object data. Dynamic blocks in Klaviyo emails can now reference Custom Object fields using Liquid templating. A subscription confirmation email can list every product in the upcoming box by name, image, and description — pulled directly from the object, not hard-coded or approximated.

Five Ecommerce Use Cases for Custom Objects

The five use cases below represent the highest-ROI applications we've seen and that Klaviyo's own documentation highlights. Not every brand will use all five — start with the one that matches your business model most directly.

1. Subscription Box Content Personalization

For subscription brands, Custom Objects are the single most impactful upgrade available in Klaviyo right now. Create a SubscriptionBox object with fields for each box's contents, ship date, and tier. Once populated, you can send a pre-shipment email that lists every product in the upcoming box by name — personalized to each subscriber's actual box, not a generic "your box is on its way" message. Klaviyo's benchmark data shows personalized post-purchase flows drive 20–30% of total email revenue for high-performing accounts. A box-specific pre-shipment email consistently outperforms generic shipping confirmations on open rate by 15–25% in our experience with subscription clients.

2. Loyalty Program Tier Flows

Connect your loyalty platform (LoyaltyLion, Yotpo, Smile.io) to Klaviyo via Custom Objects and create a LoyaltyAccount object with fields for current tier, points balance, points-to-next-tier, and tier change date. This unlocks: tier-change celebration emails that trigger automatically when a customer earns a new tier, points-expiry reminder flows, and promotional campaigns that segment by tier and reference each customer's actual points balance in the email body. "You have 847 points — that's $8.47 off your next order" converts significantly better than "Spend your rewards today."

3. B2B Purchase-Frequency Segmentation

B2B brands using Shopify's B2B portal often have account-level data — buying frequency by category, contract terms, assigned rep — that doesn't map cleanly to standard Klaviyo contact properties. A B2BAccount Custom Object can store company name, assigned rep, contract tier, and category purchase history. This enables account-level flows (not just contact-level), rep-signed email sequences, and reorder reminders triggered by each account's typical repurchase cycle rather than a blanket 30-day wait. Our Klaviyo AI flows retention guide covers complementary automation patterns that pair well with this data layer.

4. Warranty and Post-Purchase Product Registration

Brands selling products with warranty periods can create a ProductRegistration object with fields for registered product SKU, purchase date, and warranty expiry date. This drives: warranty expiry reminder flows (triggered X days before expiry), reorder or upgrade offers timed to product end-of-life, and service reminder sequences for brands with maintenance-based business models. It's a use case standard profile properties simply cannot handle without collapsing multi-product registration data into unusable strings.

5. Multi-Pet or Multi-Person Household Personalization

Pet brands, family product brands, and personal care brands often sell to customers with multiple "profiles" inside a household — multiple pets with different breeds and life stages, multiple children with different ages and sizes. A HouseholdProfile object with fields for each member (name, species/age, relevant attributes) lets you reference specific household members in product recommendations and replenishment flows. Instead of "time to restock your pet's food," you can send "Tucker's 30-lb bag of salmon formula is probably running low — here's a quick reorder link." Brands that have implemented this type of hyper-personalization see 26% higher email open rates on average (Campaign Monitor, 2025).

How to Set Up Your First Custom Object (Step-by-Step)

Setup has two phases: defining the schema in Klaviyo, and populating it with real data from your source systems.

Phase 1: Define the Schema in Klaviyo

1. Navigate to Settings → Custom Objects in your Klaviyo dashboard.
2. Click Create Object Type and give it a name (e.g., SubscriptionBox — use PascalCase, no spaces).
3. Add fields: for each field, specify a name, a data type (String, Number, Date, Boolean, or List), and whether it's required.
4. Save the schema. The object type is now available to attach to profiles.

Keep your first schema simple — 4–6 fields maximum. You can add fields later without breaking existing data, but starting lean makes validation easier.

Phase 2: Populate the Object with Data

Custom Objects are populated via Klaviyo's API endpoint POST /api/custom-objects/ with the object type, the associated profile identifier (email or external ID), and a JSON payload matching your schema. Most brands use one of three approaches:

• Native integration: If your subscription, loyalty, or commerce platform has a Klaviyo integration that supports Custom Objects (check the integration docs — not all do yet), you can configure it to sync automatically on data changes.
• Klaviyo API + webhook: Set your upstream platform (Recharge, Bold Subscriptions, etc.) to POST to a webhook on relevant events. A lightweight middleware function transforms the payload and forwards it to Klaviyo's Custom Objects API.
• Bulk import: For initial population of historical data, Klaviyo supports a CSV import for Custom Objects — useful for getting existing loyalty or subscription data loaded before you wire up the live sync.

Once data is flowing, verify in a test profile: open a contact record and check that the Custom Object appears under the new "Custom Objects" tab on the profile page.

Connecting Custom Objects to Flows, Segments, and Campaigns

With your Custom Object defined and populated, the data is available across three key parts of the platform. Here's exactly where each integration point lives.

In Flows: Object Field Change Triggers

In the Flow builder, open the trigger selector and choose Custom Object Field Changed. Select your object type, the specific field to watch, and the condition (changed to a specific value, increased above a threshold, etc.). The flow will fire for every profile where that condition is met — in real time as data syncs, not on a delay.

Use this for: tier-change celebrations, renewal reminders, expiry warnings, and any business event that's captured in your Custom Object schema rather than as a standard Klaviyo event.

In Segments: Custom Object Filters

In the Segment builder, select Custom Object as the filter category. You'll see all your defined object types listed. Select an object type, then drill into the specific field you want to filter on, with the same operators available as standard segment filters (equals, contains, greater than, within date range, etc.).

The power here is cross-referencing: you can combine Custom Object filters with standard behavior filters. "Loyalty tier is Gold AND placed an order in the last 30 days AND lives in the top 10 US markets" — a segment that was previously impossible to build natively. For a deeper look at how behavior-based segmentation fits into a full lifecycle strategy, see our guide to email lifecycle sequences for ecommerce.

In Email Content: Liquid Templating

Custom Object fields are available in email templates via Liquid. Reference them with the dot-path notation: {{ customer.custom_objects.SubscriptionBox.ship_date }}. For list fields (like a list of products inside a box), use a Liquid for loop to iterate and render each item with its own template block.

One practical note: always include a fallback value (| default: "your order") for Custom Object references in case the object isn't populated for a given profile. Flows with empty Liquid variables that don't have a default render as blank strings, which breaks email copy in ways that are hard to QA at scale.

Atlas's email and SMS marketing service includes full Klaviyo architecture — including Custom Objects setup, data integration, and flow builds — for brands that want this implemented correctly from the start rather than reverse-engineered after the fact.

FAQ: Klaviyo Custom Objects for Ecommerce Brands

What are Klaviyo Custom Objects and how do they differ from regular profile properties?

Klaviyo Custom Objects are structured datasets you define — schemas with typed fields — that attach directly to customer profiles. They differ from standard profile properties in two key ways: first, they can hold complex, nested data (like a subscription box with 12 individual product records), not just flat key-value pairs; second, each Custom Object can have its own schema with multiple typed fields (string, number, date, boolean, list), rather than a single untyped value. The result is that you can store and use genuinely complex business data inside Klaviyo — subscription tier history, loyalty point transactions, B2B contract details — and reference any field in that data inside flow conditions, segment filters, and email personalization blocks.

Do I need a developer to set up Klaviyo Custom Objects?

For the Custom Object schema definition and basic Klaviyo UI setup, no developer is required — Klaviyo's interface walks you through defining the object type, field names, and data types. However, populating Custom Objects with data from external systems (your subscription platform, loyalty app, or ERP) does require connecting those systems via Klaviyo's API or a supported integration. If your data source has a native Klaviyo integration (Recharge, LoyaltyLion, Yotpo), setup is mostly configuration. If you're connecting a custom or less common platform, you'll need API work — either from your dev team or an agency partner.

Which Klaviyo plan includes Custom Objects?

Klaviyo Custom Objects are available on Email and Email + SMS plans. As of October 16, 2026, the feature is generally available to all accounts — there is no separate add-on or enterprise-only gate. Access the feature under Settings → Custom Objects in your Klaviyo dashboard. If you don't see it, confirm your account is on a paid plan and that your account region has received the GA rollout (Klaviyo staged the GA release across regions over a 48-hour window starting October 16).

Can I use Custom Objects data in Klaviyo SMS flows as well as email?

Yes. Custom Objects data is available for personalization in both email and SMS content blocks, and can be used as trigger conditions and segment filters for flows that include SMS steps. If you're running an Email + SMS plan, any Custom Object field you reference in an email can be referenced identically in an SMS message body or flow branch. This makes it possible to build fully cross-channel sequences where both the email copy and the SMS copy reference the same underlying data — for example, a loyalty member's current points balance or a subscriber's upcoming box date.

How long does it take to see results from Custom Objects personalization?

Brands typically see measurable results within the first 30–60 days of activating Custom Objects flows, depending on list size and flow volume. The fastest wins come from subscription brands using box-content personalization in pre-shipment emails, where open rates often jump 15–25% compared to generic shipping confirmations. Loyalty tier personalization in promotional campaigns shows results on the first send — often within the first week of activation. Longer-term, the 20–30% email revenue lift Klaviyo cites for high-performing personalized accounts compounds over multiple quarters as you build more flows and refine your segment logic.