How to Create a Custom Property in Klaviyo

Klaviyo empowers marketers to collect, store, and leverage valuable customer information through its versatile custom properties feature. These specialized data fields allow you to track unique customer attributes beyond standard profile information, enabling highly personalized marketing campaigns. Custom properties serve as the foundation for advanced segmentation strategies, dynamic content creation, and automated workflows that speak directly to your customers’ preferences and behaviors.

What Are Custom Properties in Klaviyo?

Custom properties function as unique data fields attached to contact profiles in Klaviyo, extending beyond default fields like name and email. These flexible attributes allow you to collect and store any information relevant to your marketing strategy. Custom properties transform how you understand and communicate with your audience by providing deeper insights into their preferences, behaviors, and characteristics.

Each custom property represents a specific piece of information about your contacts that standard fields don’t capture. You might track clothing sizes, birthday dates, survey responses, or product preferences—virtually any data point valuable to your business. These properties become powerful tools for creating personalized experiences across all customer touchpoints.

The beauty of custom properties lies in their versatility and unlimited potential. Klaviyo places no restrictions on the number of custom properties you can create, giving you complete freedom to design a customer data structure that perfectly aligns with your business needs and marketing goals.

Benefits of Using Custom Properties

Custom properties dramatically enhance your marketing capabilities by providing deeper customer insights. They allow you to create highly targeted segments based on specific attributes, preferences, or behaviors that matter most to your business. This granular segmentation ensures your messages reach the right people with relevant content.

Your email campaigns become more personal and impactful when powered by custom property data. Dynamic content blocks can automatically display different information based on a customer’s preferences, purchase history, or demographic details. This level of personalization creates more engaging experiences that resonate with recipients on an individual level.

Custom properties also enable sophisticated automation workflows based on specific customer attributes. You can trigger birthday emails when someone’s birthday approaches, send size-specific product recommendations, or create re-engagement campaigns for customers with particular interests. These automated sequences deliver timely, relevant content without requiring manual intervention.

Types of Data You Can Track

Custom properties accommodate various data types to match your specific tracking needs:

Customer demographics:

• Age ranges that segment your audience by generation
• Geographic locations for region-specific promotions
• Income brackets for tailored product recommendations
• Education levels to adjust messaging complexity

Shopping preferences:

• Preferred product categories they consistently browse
• Favorite brands they’ve purchased or viewed
• Price sensitivity indicators based on purchase history
• Shopping frequency patterns over time

Communication preferences:

• Preferred email frequency (daily, weekly, monthly)
• Content topic interests for newsletter personalization
• Preferred communication channels (email, SMS, push)
• Optimal sending times based on open history

Engagement metrics:

• Loyalty program status and point balances
• Referral activity tracking for advocacy programs
• Survey response data for sentiment analysis
• Event attendance history for offline engagement

Each custom property becomes a valuable data point that helps you understand your customers better and create more relevant marketing experiences. The key lies in thoughtfully planning which properties will provide the most actionable insights for your specific business needs.

How to Add Custom Properties to Klaviyo

Adding custom properties to Klaviyo involves several methods, each suited to different scenarios and data volumes. The platform’s flexibility allows you to choose the approach that best fits your current needs and technical capabilities. Whether you’re importing existing customer data or collecting new information, Klaviyo provides straightforward options for creating and populating custom properties.

CSV Upload Method for Bulk Updates

The CSV upload method offers an efficient way to add custom properties to multiple profiles simultaneously. This approach works particularly well when migrating data from another platform or updating information for a large segment of your audience. The process follows a structured format that maintains data integrity while allowing for customization.

Preparing your CSV file correctly ensures a smooth import process without data corruption. Start by organizing your spreadsheet with email addresses in the first column, followed by any standard fields like first and last names. Then add columns for each custom property you want to create or update, using clear, consistent header names that reflect the property’s purpose. Ensure all data follows consistent formatting, especially for dates and numerical values.

When uploading your file to Klaviyo, the system guides you through mapping your CSV columns to profile properties. For any column that doesn’t match an existing property, simply type a new name in the field and select “Create New Field” from the dropdown. This creates the custom property in your account and populates it with the corresponding values from your CSV file, all while preserving existing subscription statuses if you choose.

Manual Addition on Individual Profiles

Sometimes you need to update custom properties for just one contact or a small handful of profiles. Klaviyo’s interface makes this process straightforward through direct profile editing. This method works well for testing new properties or making quick adjustments to specific customer records.

Accessing a profile’s custom properties section reveals all current data and provides options for additions or modifications. Navigate to the Profiles tab, select the specific contact, and scroll to the Custom Properties area within their Information section. Here you’ll find all existing custom properties along with their current values, presented in an organized, editable format.

Adding a new custom property takes just a few clicks and requires minimal information. Click the “Add custom property” button, enter your property name following your naming conventions, and provide the corresponding value. The system immediately saves this information to the profile, making it available for segmentation, personalization, and automation without any additional steps or processing time.

Signup Forms and Preference Pages

Collecting custom property data directly from customers ensures accuracy and relevance while building your database organically. Klaviyo’s form builder allows you to create custom fields that capture exactly the information you need through user-friendly interfaces on your website. This approach puts customers in control of their data while providing you with valuable insights.

Designing effective signup forms requires balancing information collection with user experience. Start by identifying the most valuable data points for your marketing strategy, then create concise, clear form fields to collect this information. Dropdown menus, radio buttons, and checkboxes often work better than open text fields because they ensure consistent data formatting and make the form easier to complete.

Preference center pages provide existing subscribers with opportunities to update their information and share additional details. These pages typically include both required fields (email address) and optional custom property fields (interests, preferences, demographics). When customers update these fields, Klaviyo automatically saves the new information to their profiles, keeping your database current without requiring manual updates or imports.

API Integration for Automated Updates

For businesses with technical resources, Klaviyo’s API offers powerful capabilities for creating and updating custom properties programmatically. This method enables real-time data synchronization between your website, CRM, or other business systems and your Klaviyo account. API integration works particularly well for dynamic data that changes frequently or requires immediate updates.

The Identify API serves as the primary method for creating or updating profile information, including custom properties. When implementing this API, you’ll send structured data objects that include the contact’s identifier (typically email) along with any custom properties you want to create or update. The API automatically handles property creation if it doesn’t already exist, making implementation relatively straightforward for developers.

Track API calls complement the Identify API by attaching custom property data to specific events. This approach allows you to capture contextual information at the moment an action occurs, such as recording product preferences during browsing sessions or capturing survey responses as they’re submitted. The resulting data becomes immediately available for segmentation and personalization, enabling real-time marketing responses to customer behaviors.

Using Custom Properties in Marketing Campaigns

Custom properties transform ordinary marketing campaigns into personalized experiences that resonate with individual customers. By leveraging the unique data points you’ve collected, you can create highly targeted communications that speak directly to each recipient’s interests, preferences, and behaviors. This personalized approach significantly improves engagement rates and drives better marketing outcomes.

Creating Powerful Audience Segments

Segmentation based on custom properties allows you to divide your audience into precisely defined groups for targeted messaging. These segments can be as broad or specific as your strategy requires, from simple demographic divisions to complex behavioral patterns. The key lies in identifying which properties create meaningful distinctions within your customer base.

Property-based segments enable you to tailor your messaging to specific audience characteristics. For example, you might create segments based on clothing size preferences to promote relevant products, or use communication frequency preferences to respect how often customers want to hear from you. These targeted approaches ensure your messages feel relevant rather than generic or intrusive.

Combining multiple custom properties creates even more sophisticated segmentation possibilities. You might target customers who both prefer a specific product category and have birthdays approaching, or identify high-value customers who haven’t purchased in the last 60 days. These multi-dimensional segments allow for highly specific targeting that addresses particular customer needs or opportunities.

Personalizing Email Content Dynamically

Dynamic content blocks powered by custom properties create truly personalized email experiences. These elements automatically adjust what each recipient sees based on their profile data, ensuring maximum relevance without creating multiple campaign versions. This approach saves time while delivering highly tailored content.

Klaviyo’s template language makes implementing dynamic content straightforward:

Product recommendations:

• Display items in the customer’s preferred size category
• Feature products in their favorite color preferences
• Showcase items from brands they’ve previously purchased
• Highlight products within their typical price range

Content personalization:

• Adjust messaging tone based on customer segments
• Show different images reflecting personal interests
• Modify offers based on loyalty status or purchase history
• Present location-specific information for regional customers

Offer customization:

• Tailor discount amounts based on customer value tiers
• Adjust free shipping thresholds to match typical order values
• Personalize gift with purchase based on product preferences
• Create urgency with countdown timers for birthday offers

Testing dynamic content thoroughly ensures it displays correctly for all possible property values. Always include default content for cases where a customer doesn’t have the relevant property data, preventing blank or broken email sections that could harm the user experience.

Building Automated Flows with Custom Properties

Automated flows become more powerful and precise when triggered or filtered by custom properties. These workflows deliver timely, relevant messages based on specific customer attributes or changes to those attributes. This automation ensures consistent communication while maintaining personalization at scale.

Birthday flows represent a classic example of custom property automation. By collecting birth dates as custom properties, you can trigger personalized birthday messages with special offers or recognition. The flow activates automatically when a customer’s birthday approaches, delivering timely congratulations without requiring manual intervention.

Preference-based flows allow you to respond to changes in customer data automatically. When someone updates their preferences through your preference center, you can trigger flows that acknowledge these changes and begin delivering more relevant content. For example, if a customer indicates interest in a new product category, a flow might send an introduction to that category with popular product recommendations.

Best Practices for Custom Property Management

Effective management of custom properties ensures your data remains organized, accurate, and valuable for marketing purposes. Following established best practices helps prevent common pitfalls like duplicate properties, inconsistent naming, or data quality issues that could undermine your marketing efforts.

Establishing Naming Conventions

Consistent naming conventions create clarity and prevent duplicate properties in your Klaviyo account. Well-structured property names make it easier for team members to understand what each property represents and how it should be used in marketing campaigns.

Choose descriptive names that clearly indicate the property’s purpose without being unnecessarily long. For example, “ShirtSize” is more descriptive than “Size” but shorter than “CustomerPreferredShirtSize.” This balance between clarity and brevity makes properties easier to work with when building segments or dynamic content.

Follow a consistent capitalization pattern across all properties to prevent accidental duplicates. Klaviyo treats “favorite_color” and “FavoriteColor” as separate properties, which could split your data across multiple fields. Decide whether you’ll use camelCase, snake_case, or another pattern, then apply it consistently to all new properties.

Data Formatting and Validation

1. Standardize date formats across all time-based properties to ensure consistent functionality in segments and flows. Use YYYY-MM-DD format for maximum compatibility with Klaviyo’s systems.
2. Implement validation rules in forms and API calls to prevent incorrect data from entering your system. For example, restrict size selections to predetermined options rather than allowing free text entry.
3. Create clear documentation for each custom property, including its purpose, expected format, and valid values. This reference helps maintain consistency as your team grows.
4. Regularly audit your custom properties to identify and correct formatting inconsistencies or outdated information that could affect campaign performance.
5. Consider using dropdown menus or radio buttons instead of text fields when collecting data through forms to enforce consistent formatting automatically.

Maintaining Property Organization

Regular audits of your custom property library help identify unused or duplicate properties that might clutter your account. Schedule quarterly reviews to assess which properties are actively used in segments, flows, or dynamic content, and consider archiving those that no longer serve a purpose in your marketing strategy.

Documentation plays a crucial role in maintaining property organization, especially as your team grows. Create a centralized reference guide that lists all custom properties, their purposes, expected values, and where they’re used in your marketing programs. This resource helps prevent duplicate properties and ensures consistent usage across campaigns.

Property grouping strategies can help manage complex data structures more effectively. Consider using prefixes to categorize related properties (e.g., “Pref_EmailFrequency” and “Pref_ContentTopics” for preference-related properties). This approach creates visual organization in your property list and makes it easier to find specific properties when building segments or dynamic content.

Leveraging Custom Properties for Advanced Marketing

Custom properties unlock sophisticated marketing capabilities that go beyond basic segmentation and personalization. When strategically implemented, these data points enable predictive marketing, enhanced customer journeys, and truly personalized experiences across all touchpoints. The advanced applications of custom properties represent the cutting edge of data-driven marketing.

Predictive Marketing with Property Data

Custom properties provide the foundation for predictive marketing strategies that anticipate customer needs. By analyzing patterns in your property data, you can identify likely future behaviors and preferences, allowing you to proactively address customer needs before they’re explicitly expressed.

Purchase cycle prediction becomes possible when you track timing data in custom properties. By recording dates of recurring purchases (like skincare products or subscription renewals), you can calculate average intervals between orders and predict when a customer might be ready to buy again. This allows you to send timely reminders or offers when they’re most likely to convert.

Interest evolution tracking helps you understand how customer preferences change over time. By comparing current interests with historical data stored in custom properties, you can identify emerging patterns and adjust your marketing accordingly. For example, if you notice a customer shifting from casual to professional clothing purchases, you might emphasize your business attire collection in future communications.

Enhancing Customer Journey Mapping

Custom properties provide crucial context for understanding and optimizing the customer journey. By tracking touchpoints, preferences, and behaviors as properties, you can create more accurate journey maps that reflect actual customer experiences rather than theoretical pathways. This data-driven approach reveals opportunities for improvement and personalization.

Journey stage indicators stored as custom properties help you deliver stage-appropriate content to each customer. By tracking where someone falls in your defined journey (awareness, consideration, purchase, loyalty), you can ensure your communications match their current relationship with your brand. This prevents the common mistake of sending awareness-focused content to existing customers or advanced information to newcomers.

Touchpoint tracking through custom properties creates a comprehensive view of how customers interact with your brand. By recording which channels they engage with (email, social, website, in-store) and which content types they respond to, you can optimize future communications to focus on their preferred touchpoints. This targeted approach improves engagement while reducing wasted efforts on low-performing channels.

Personalized Customer Experiences

Custom properties enable truly personalized experiences that adapt to individual customer preferences across all marketing channels. This comprehensive personalization creates a cohesive brand experience that recognizes and responds to each customer’s unique characteristics and behaviors.

Website personalization becomes more effective when powered by Klaviyo custom properties. By passing property data to your website through JavaScript or API integrations, you can dynamically adjust content based on known customer preferences. Product recommendations, featured categories, and even homepage banners can reflect individual interests stored in custom properties.

Cross-channel consistency ensures customers receive coherent messaging regardless of where they interact with your brand. Custom properties provide the central data repository that informs communications across email, SMS, social media, and other channels. This unified approach prevents the jarring experience of receiving contradictory or redundant messages across different platforms.

Taking Your Custom Properties to the Next Level

Maximizing the value of your custom properties requires ongoing optimization and strategic implementation. As your marketing program matures, you’ll discover new ways to leverage these data points for increasingly sophisticated campaigns. The following approaches represent advanced techniques for those who have already mastered the basics of custom property usage.

Automated Property Updates

Automated property updates ensure your customer data remains current without manual intervention. These systems continuously refresh property values based on customer behaviors, preferences, and interactions, maintaining an accurate profile for each contact in your database. This automation saves time while improving data quality.

Flow-based property updates provide a user-friendly method for keeping data current. Using Klaviyo’s visual flow builder, you can create workflows that automatically update custom properties when specific events occur or conditions are met. For example, a flow might update a “LastProductCategory” property whenever someone makes a purchase, or increment an “EmailEngagementScore” property when they click on specific content.

API-driven updates offer more sophisticated automation possibilities for businesses with technical resources. By connecting your website, product database, or CRM to Klaviyo through API integrations, you can synchronize data in real-time across systems. This approach ensures that any change in customer information immediately updates the corresponding custom properties in Klaviyo, maintaining perfect consistency across platforms.

Scaling Your Custom Property Strategy

As your business grows, your custom property strategy must scale accordingly. This expansion involves not just adding more properties but developing a comprehensive framework that supports increasingly complex marketing initiatives while maintaining data integrity and usability. A thoughtful scaling approach prevents the common pitfalls of property proliferation.

Property governance becomes essential as your database expands. Establish clear guidelines for property creation, including approval processes, documentation requirements, and naming conventions. This governance prevents the chaos that can result from uncontrolled property creation and ensures new properties align with your overall data strategy.

Integration planning helps accommodate growth across multiple systems and channels. As you add new marketing tools or sales platforms, consider how custom properties will flow between these systems and Klaviyo. Develop standardized approaches for property mapping and data synchronization that can be applied consistently as your technology stack evolves.

Measuring Custom Property Impact

Measuring the impact of your custom property strategy provides insights for ongoing optimization. By tracking how property-based segmentation and personalization affect key performance indicators, you can identify which properties deliver the greatest value and where additional data collection might improve results.

Campaign comparison testing reveals the effectiveness of custom property personalization. Create controlled tests comparing standard campaigns against versions using custom property personalization, measuring differences in open rates, click-through rates, conversion rates, and revenue generated. These comparisons quantify the value of your personalization efforts and justify continued investment in data collection.

Property utilization analysis helps identify which custom properties provide the most marketing value. Regularly review which properties are actively used in segments, flows, and dynamic content, and assess their impact on campaign performance. This analysis might reveal that certain properties consistently drive strong results while others rarely influence marketing outcomes, guiding future data collection priorities.

Start Creating Powerful Custom Properties Today

Custom properties represent one of Klaviyo’s most powerful features for creating personalized, effective marketing campaigns. By thoughtfully collecting and leveraging customer data through custom properties, you can transform generic marketing into highly targeted communications that resonate with individual recipients. This personalized approach drives better engagement, stronger customer relationships, and ultimately, increased revenue.

The process begins with identifying which customer data points would most benefit your specific marketing strategy. Consider what information would help you create more relevant content, better segment your audience, or develop more effective automated workflows. These strategic considerations should guide your custom property implementation rather than collecting data simply because you can.

Take action today by auditing your current customer data, identifying gaps in your knowledge, and developing a plan to collect and utilize that information through Klaviyo’s custom properties. Start small with a few high-impact properties, measure their effectiveness in your marketing campaigns, and gradually expand your strategy based on those results. With each step, you’ll build a more comprehensive customer database that powers increasingly sophisticated marketing initiatives.