Top 9 UTM Mistakes That Can Ruin Your Campaign Tracking

Table of Contents

Updated: November 25, 2025

UTM parameters (Urchin Tracking Module) are used in Google Analytics 4 (or other analytics tools) to track the source of traffic. However, many people misuse them, which can lead to data confusion or inaccuracies.

Below is a summary of common mistakes and precautions:

Misusing uppercase and lowercase (most common!)

Issue: UTM parameters are case-sensitive.
Example: utm_source=Facebook and utm_source=facebook are recognized as two different sources.
Recommendation: Use lowercase consistently, e.g., utm_source=facebook.

Issue: Using spaces or non-English characters in UTM parameters will encode spaces as %20 or +, and non-English characters will be URL-encoded. This can result in garbled or duplicate entries in reports.
Example: utm_campaign=(non-English characters)&utm_medium=cpc
Recommendation: Use only English letters, numbers, underscores, or hyphens, e.g., utm_campaign=double11_promo_2025&utm_medium=cpc.

Issue: Adding UTM parameters to internal links will make GA4 treat the click as a new session source.
Example: Internal links used for tracking with utm_source=email → GA4 treats it as a new source.
Recommendation: Never use UTM parameters on internal links.

Issue: If the same UTM parameter is repeated in a URL, GA4 takes the last value.
Example: utm_campaign=spring_sale1&utm_campaign=spring_sale2 → GA4’s utm_campaign dimension will be spring_sale2.
Recommendation: Ensure each UTM parameter is used only once.

Issue: UTM parameters that are too long (common when using many dynamic parameters) or contain special characters like # can be difficult to read and may fail to be parsed by some tools.
Example: utm_source=Facebook#channel@official&utm_medium=social&utm_campaign=spring_sale_2025_version_final
Recommendation: Keep parameters short, avoid special characters like #, and use only letters, numbers, underscores _, or hyphens -.

Issue: utm_source, utm_medium, and utm_campaign should use official recommended values to map to the correct channels; otherwise, channels may be classified as Others.
Example: utm_medium=marketing1 → It is unclear whether it is email, cpc, or social.
Recommendation: Follow official recommended values, e.g., utm_medium should be cpc, email, or social.

Issue: Mixing up UTM parameters can cause misinterpretation. utm_source is for traffic source, utm_medium is for medium type, and each UTM parameter has a specific purpose.
Example: utm_source=cpc&utm_medium=facebook&utm_campaign=spring_sale_2025
Recommendation: Don’t confuse parameters; use official recommended values for utm_medium.

Correct standards (industry best practices):

Parameter	Recommended Examples	Description
utm_source	google / facebook / wahtsapp/ tiktok	Traffic source platform
utm_medium	cpc / cpm / social / email / qr_code	Marketing medium type
utm_campaign	double11_2025 / spring_promo	Campaign name (adding year is recommended)
utm_term	Keywords (for paid search)
utm_content	banner_a / video_v2 / logoposition	Differentiates multiple creatives for same ad

Issue: Missing required UTM parameters may result in traffic being categorized as (direct)/(none).
Example: utm_source=facebook&utm_campaign=spring_sale_2025_version_final
Recommendation: There are five common UTM parameters, with three most frequently used: utm_source, utm_medium, and utm_campaign. utm_source and utm_medium are essential for channel classification; missing them will cause incorrect channel mapping.

Issue: Some short link services may overwrite or remove original UTM parameters.
Recommendation: Test short links to ensure UTM parameters are not overwritten or removed.

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