# Adding Custom UTM Codes to Your Newsletter

## Learn how to add dynamic UTM parameters to your newsletters to track subscriber engagement and campaign performance.

#### Overview

Letterhead now allows you to add **custom UTM codes** to your newsletters. This helps you track where your traffic comes from when subscribers click links in your email.

#### **Using a dynamic value**

A dynamic UTM value changes based on the subscriber’s data. You can do this by using [**Letterhead personalization (merge) tags**.](https://help.tryletterhead.com/personalization-tags?hsLang=en#:~:text=Complete%20list%20of%20personalization%20tags%3A%C2%A0)

For example, you can use a tag like {{CRMID}} as your UTM value. When the newsletter is sent, the tag automatically populates with each recipient’s unique data.

**⚠️  Note** Only **Letterhead-supported merge tags** can be used for dynamic UTM values. You can find the full list of available tags [here](https://help.tryletterhead.com/personalization-tags?hsLang=en#:~:text=Complete%20list%20of%20personalization%20tags%3A%C2%A0).

Dynamic UTMs are especially useful for tracking subscriber-level engagement ,helping you see which subscribers clicked which links.

#### **How to Add UTM Codes to Your Newsletter**

Follow these steps to enable UTM tracking in your newsletter:

1. **Go to the “Preview and Schedule” step :**  
In your newsletter scheduling flow, open the “Preview and Schedule” screen. You’ll see a **UTM Tracking** section below “Send Test Email”. This appears for both new and existing letters.
2. **Enable UTM Tracking:**  
Toggle UTM Tracking to ON.
3. **Enter your UTM parameters**  
   - In the **Key** field, enter the UTM parameter key (e.g., utm_source, utm_medium, or utm_campaign).  
   - In the **Value** field, enter a dynamic value using a merge tag without space (e.g., {{CRMID}} )

4. **Add multiple UTM parameters (optional)**

You can add more than one UTM parameter by clicking **\+ Add link parameter**.

5. **Publish your letter**  
Once published, your UTM parameters will automatically be appended to every link in your newsletter as query strings (e.g., ?utm_source=newsletter&utm_campaign={{CRMID}}).

#### **Example**

If you set:

- **Key:** utm_campaign  
- **Value:** {{CRMID}}

Then the final link in your newsletter might look like this:

https://example.com/article?utm_campaign=12345

(Here, 12345 is replaced dynamically with the subscriber’s unique CRM ID.)

#### **Why Use Custom UTMs?**

Custom UTM tracking lets you:

- Measure traffic from specific newsletters or campaigns.
- Attribute clicks to individual subscribers (with dynamic tags).
- Better understand engagement and marketing performance.