If your company is going to place ads or content on third-party websites, you’ll need a way to work out how effective those campaigns have been. Tagging your advertising links correctly is one simplest ways to flesh out your GA4 reporting with actionable data.
UTM parameters are not a new concept, but we often see them used incorrectly. Getting them right does not require technical expertise, but you need to understand some general concepts and you’ll need a consistent approach.
These are the main topics that we will look at in this post:
- What are UTM parameters?
- How to properly tag links with UTM parameters
- How UTM tagged links help with GA4 reporting
- Why you should not tag internal links with UTM parameters
FYI: you don’t need to remember this, but UTM stands for Urchin Tracking Module.
What are UTM parameters?
UTM parameters are small pieces of text that you append to the end of the URL your ads or sponsored content will link to. When someone clicks a link that contains UTM parameters, Google Analytics reads those values and records them alongside all of the other data they are collecting. You’ll then have a lot more context in your advertising reports.
What do UTM parameters look like?
A UTM-tagged URL looks something like this (just assume you work at NASA):
https://www.nasa.gov/landing-page/?utm_source=mars-travel-directory&utm_medium=display&utm_campaign=black-friday-promotion&utm_content=yellow-moon-banner
In this example, everything after the ? are the UTM parameters and their values. The URL still takes the user to the same page, but Google Analytics now knows that the visit came from a display ad we’ve called yellow-moon-banner placed on the Mars travel directory as part of a Black Friday promotion campaign.
What are the five main UTM parameters?
There are five standard UTM parameters, two of which are considered as required by Google:
- utm_source (required)
Where the traffic is coming from. This is typically the name of the website, newsletter, or content where your ad is placed. - utm_medium (required)
The marketing channel. Common values include display, email, cpc, or sponsored. - utm_campaign (optional)
The name of the specific campaign this ad belongs to. - utm_content (optional)
Used to differentiate between multiple ads within the same campaign. - utm_term (optional)
Originally designed for paid search keyword tracking. Handled automatically by Google Ads when auto-tagging is turned on.
For most third-party advertising placements, utm_source, utm_medium, and utm_campaign will give you the minimum reporting detail you need.
There are 5 other UTM parameters, but we won’t cover them here. We will just mention that you will need utm_id if you upload campaign data manually to GA4. Google Analytics doesn’t currently utilise the others in reports.
How to properly tag links with UTM parameters
Tagging your ad links with UTM parameters is straightforward, but consistency is crucial. If different people in your team are building tagged URLs without agreed conventions, your GA4 reports will quickly become fragmented and difficult to read.
Should you build UTM URLs manually or use a tool?
Google provides a free Campaign URL Builder that lets you fill in each parameter value and then generates the tagged URL for you.
This tool reduces the risk of typos and formatting errors, and it is the approach we recommend for anyone who is not yet building tagged URLs very often. It won’t, however, ensure that you are using a good parameter value naming convention. That’s up to you and your team.
For teams managing larger volumes of campaigns, a spreadsheet-based URL builder using a formula is a more practical solution. By making a custom spreadsheet based tool you can also speed things up with pre-defined values, perhaps via drop-down lists.
What naming conventions should you use?
Before coming up with your own values, we strongly recommend that you consider how Google determines channel group definitions. By using the values Google looks for by default you will help them organise your data into the correct GA4 reports.
Next, consider how you type your values. This is where many companies run into problems. UTM values are case-sensitive, which means Display and display will appear as two separate entries in GA4. Establishing a clear naming convention before you start, and sticking to it across every campaign, is essential.
Here are some useful tips that will point you in the right direction:
- Use lowercase for all UTM values. If you build a tool in a spreadsheet, force all values to lowercase.
- Use hyphens rather than spaces or underscores to separate words.
- Keep values short but descriptive enough to be immediately recognisable in a report.
- Again, check the GA4 channel groups documentation for the default medium values.
- Beyond the required UTM parameters, use the others where they make sense so they can augment your reporting even further.
- Whether solo or in a team, ALWAYS follow your established naming conventions.
Form good habits now. Your future self will thank you later.
Does every ad link need a UTM tag?
We recommend that you tag every advertising link. The only exception being on pay-per-click (PPC) advertising platforms where auto-tagging is enabled. In those cases, everything will be taken care of for you.
Remember, the data in your reports is there to help you and your team make marketing and business decisions. If you are missing the information needed to decide what worked and what didn’t, you are back to just guessing.
We have been generally discussing website advertising in this post, but everything we’ve discussed would also apply to more diverse mediums. That could include social media, email signatures, QR codes (with URL links), links in SMS/txt messages, links in PDF files, etc.
How UTM tagged links help with GA4 reporting
When a user arrives at your website via a UTM-tagged link, GA4 captures the parameter values and associates them with that session, user or event. Google Analytics sees everything in terms of users, sessions and events. These are the data scopes. So, any subsequent user interactions that trigger events such as purchases or form submissions are then linked to the appropriate data scopes in your reports, and accompanied by your parameter information.
Where do you find UTM data in GA4?
In GA4, UTM data surfaces though various reports. For example, by changing the primary dimension to Session source, Session medium or Session campaign, you can see exactly which tagged campaigns are driving traffic and how those visitors are behaving on your site.
For a more detailed breakdown, the Explorations section of GA4 allows you to build custom reports that cross-reference UTM parameters with any event or conversion data you are collecting. This is where we often discover highly actionable insights for clients of our website analytics services.
Can UTM data help you make better advertising decisions?
Yes, and that is precisely the point. This is how you begin to answer questions such as which was the most effective campaign, banner design, sponsored content, etc. For example, you pay to be in an industry email newsletter – did it work? How do you know? UTM parameters on your links within that newsletter will tell you.
Over time, consistent UTM tagging builds a reliable picture of which channels, campaigns, and placements are genuinely contributing to your business objectives, rather than just generating traffic.
Why you should not tag internal links with UTM parameters
This is one of the most common UTM mistakes we see, and it causes more damage to your analytics data than most people realise. UTM parameters should only ever be used on links that point to your website from an external source. They should never be placed on links that navigate between pages within your own website.
What happens when you tag internal links with UTM parameters?
When a user clicks an internally tagged link, GA4 discards the original traffic source information on subsequent visits. So if someone arrived at your website from a paid banner ad, correctly tagged with UTM parameters, but then clicked an internal link that also had UTM parameters on it, GA4 would overwrite the original source data for any future visits. You bascially start a ripple effect which polutes attribution reporting.
We see this regularly when auditing analytics setups for new clients. The problem is almost always the result of someone applying UTM tags to promotional images, buttons, or pop-ups within their own site without understanding the consequences. Besides, there is a better way. Keep reading.
What should you do instead for tagging internal links?
If you want to track how users interact with specific links or buttons within your website, the right approach is event tracking via your Google Tag Manager setup. GTM allows you to fire custom events (which can have there own parameters) when users click specific elements, without touching the URL or interfering with session attribution. That data then flows into GA4 as events, which you can analyse without corrupting your traffic source reporting.
The rule is simple: UTM parameters belong on external links only. Everything else should be handled through proper event tracking.
Final thoughts
Tagging links correctly is one of the lower-effort, higher-impact improvements you can make to your digital marketing reporting. The mechanics are not complicated, but the discipline required to apply them consistently, especially across a team, is where most companies lose their way.
If you think your website could benefit from an audit of your current analytics configuration and on-site tracking setup, ask us about getting some help.