Tags and Custom Properties both store data on contact profiles, but they serve different purposes. Tags track dynamic, changing attributes like engagement status. Custom Properties store stable information like language preference or loyalty points. This article explains when to use each.
Contact Tags
Tags are labels you assign to contact profiles to categorize them based on behavior, source, or engagement. Tags can be added and removed easily, making them ideal for tracking dynamic data that changes over time.
How to Add Tags:
You can add tags manually in the contact profile, via Automation, through your ecommerce platform (e.g., Shopify, WooCommerce), or third-party apps (e.g., AfterShip, Yotpo Loyalty and Referrals).
Examples:
"VIP Customer"
"Engaged in Last 30 Days"
"Abandoned Cart"
Custom Properties
Custom Properties are additional data fields stored on contact profiles beyond default fields like email, name, and phone number. Unlike tags, custom properties cannot be removed – only their values can be changed. This makes them suitable for static or semi-static data that remains mostly consistent or is manually updated by the contact.
How to Add Custom Properties:
You can collect custom properties through:
Signup Forms – Add custom fields to capture preferences.
Contact Import – Map CSV columns to custom properties.
API or Integrations – Sync data from third-party apps (e.g., loyalty programs, CRMs).
Subscriber Preference Center – Let contacts update their own data.
Examples:
"Preferred Language"
"Loyalty Points"
"Membership Tier"
Tags vs. Custom Properties: Quick Comparison
Both tags and custom properties help you organize and segment contacts, but they work differently. Here's a quick comparison:
Feature | Tags | Custom Properties |
Can be removed? | Yes | No (values can change) |
Used in message personalization? | No | Yes |
Best for | Dynamic, changing data | Static or semi-static data |
Choosing Tags or Custom Properties on Import
When importing contacts from a CSV file, you can assign one tag to the entire import (e.g., "Spring 2026 Import") and map multiple columns to custom properties (e.g., Language, Product Interest, Signup Source).
Key differences:
Tags identify the import batch or source.
Custom Properties store unique data for each contact.
For example, a custom property named "Language" can hold different values (English, French, German) for different contacts. You can then use this property to segment your audience or personalize email content.
💡 Tip: If importing comma-separated values (e.g., "Languages: English, German"), use the contains operator in segment filters. Custom properties appear at the bottom of the filter dropdown under "Custom Properties."
FAQ
Can I use tags in email content?
No. Tags are for segmentation, and au triggers only. Use Custom Properties for personalization in emails, SMS, and push notifications.
Can I convert a tag into a custom property?
No. Tags and custom properties are separate tools. If you need to store tag-like data permanently, create a custom property instead.
Which should I use for segmentation?
Both can be used in segments. Use tags for temporary or behavior-based segments (e.g., "Clicked in Last 7 Days"). Use custom properties for stable attributes (e.g., "Product Interest: Skincare").
Can I rename or delete a custom property?
Custom properties cannot be renamed once created.
If you have more questions or need assistance, talk to our Support Team via In-app chat or at [email protected].