UTM parameter setup

UTM parameters are the single most important thing you control that affects how accurate Prism's attribution is. Bad UTMs don't show up as broken — they show up as inflated "Direct" traffic, mysterious orders from channels you stopped advertising on weeks ago, and ROAS numbers that don't match reality.

This guide covers what UTMs are, the five parameters, what Prism actually does with them, naming conventions, per-platform setup, and the mistakes we see most often.

If you just want the answer for one platform, jump to the per-platform cheat sheet.

The 60-second version

UTMs are query string parameters you bolt onto a URL to tell analytics tools where the traffic came from. They look like this:

https://yourstore.com/products/widget?utm_source=meta&utm_medium=paid_social&utm_campaign=spring-sale

There are five UTMs. The two that matter most for channel classification are utm_source and utm_medium. The other three (utm_campaign, utm_content, utm_term) are for breakdowns inside a channel.

If you're spending money on a paid platform, every link in every ad should have UTMs. If you're sending an email or SMS, every link should have UTMs. If you're posting organically on social, UTMs are nice-to-have but not strictly required (Prism can usually figure it out from the referrer).

How Prism classifies channels (the real answer)

When Prism receives a page view, it runs through a priority-ordered list of rules and uses the first one that matches. Understanding this order is the difference between "I'll tag everything carefully" and "I'll tag everything carefully and still know what Prism is going to do with it."

The priority order, from highest to lowest:

1. Platform click IDs (gclid, fbclid, gbraid, wbraid, ttclid, msclkid, li_fat_id, epik, ScCid, rdt_cid, twclid)
2. UTM combinations for paid traffic (e.g., utm_source=google + utm_medium=cpc → Google Ads)
3. UTM medium for owned channels (e.g., utm_medium=email → Email)
4. Referrer domain for organic traffic (e.g., referrer ends with instagram.com and no paid medium → Meta Organic)
5. Referrer fallback — any external referrer that didn't match a known pattern → Referral
6. Direct — no referrer, no UTM → Direct
7. Other — anything left over → Other

Two consequences of this order that surprise people:

• Click IDs always win. If Meta's auto-tagging slaps an fbclid onto a URL that you've already tagged utm_source=email, the visit gets classified as meta_paid. The click ID rule has higher priority than the UTM rule. Always.
• Your utm_source can get ignored. Rules at priority 2 need both utm_source AND utm_medium to match. If you set utm_source=meta but utm_medium=email, the paid-Meta rule fails, and the email rule (which only needs utm_medium) wins. You'll see this traffic as "Email", not "Meta Ads." See contradictory combos below.

The five parameters

What happens if you skip utm_campaign: The visit still classifies into the right channel, but the Campaign Drill-Down view in Prism shows it as (no campaign). You lose the ability to compare campaigns against each other within a channel, which is most of the value of campaign-level reporting. Tag it.

What happens if you skip utm_content and utm_term: Nothing breaks. These only matter if you want ad-level or keyword-level breakdowns in addition to campaign-level. For most stores, campaign-level is enough.

Naming conventions

These aren't rules Prism enforces — they're conventions that prevent you from having spring_sale, spring-sale, Spring Sale, and SpringSale show up as four different campaigns in your reports.

A workable convention for most stores:

utm_source = {platform}                              # meta, google, klaviyo, tiktok
utm_medium = {type}                                  # paid_social, cpc, email, sms, affiliate
utm_campaign = {yyyy-mm}_{descriptive-name}          # 2026-03_spring-sale
utm_content = {creative-or-ad-variant}               # video-15s-product-focus

Per-platform cheat sheet

These are the values you should use on each platform. If you're using auto-tagging features (notes after the table), you can sometimes skip manual tagging — but the cheat sheet shows what Prism is expecting to see, regardless of who put it there.

Auto-tagging vs manual tagging

Some platforms attach their own tracking parameter automatically, with no work on your side. These are reliable and Prism prefers them when available:

• Google Ads — auto-tagging is on by default in modern Google Ads accounts. It appends gclid to your final URL. You can leave manual UTMs blank if you trust your gclid. Most operators still set utm_campaign so they get a clean campaign name in non-Google tools.
• Meta Ads — does not auto-tag with UTMs. You have to set them manually in the Ads Manager URL Parameters field. The fbclid click ID is appended by Facebook's link redirector and Prism recognizes it, but you still need UTMs for campaign-level rollup.
• TikTok Ads — has an auto-tagging toggle in the Tracking section of each ad. Turn it on; it sets ttclid.
• Email/SMS tools — most (Klaviyo, Mailchimp, Postscript, Attentive) have a setting that auto-appends UTMs to every link. Turn it on once and stop thinking about it.

Worked examples

Here are concrete URLs and what Prism does with each. These all come from the same classification rules that run in production — they're not aspirational. (Every URL below is replayed through the live classifier in our test suite, so this section can't quietly drift out of date.)

Example 1: A clean Meta paid URL

https://yourstore.com/?utm_source=meta&utm_medium=paid_social&utm_campaign=2026-03_spring-sale&utm_content=video-15s

• utm_source=meta matches the Meta paid rule.
• utm_medium=paid_social is on the paid-medium list.
• Classified as Meta Ads (meta_paid).
• Campaign drill-down shows 2026-03_spring-sale. Ad creative shows video-15s.

Example 2: A Google Ads click with auto-tagging only

https://yourstore.com/?gclid=Cj0KCQjwzZmEBhCEARIsAFZQQ8x...

• gclid click ID detected → highest priority rule fires immediately.
• Classified as Google Ads (google_paid).
• No utm_campaign set, so campaign drill-down shows (no campaign). This is fine if you're cross-referencing in Google Ads' own dashboard, less fine if you want everything in Prism.

Example 3: A Klaviyo welcome flow email

https://yourstore.com/products/welcome-kit?utm_source=klaviyo&utm_medium=email&utm_campaign=welcome-flow-day-1

• utm_medium=email matches the Email rule.
• Classified as Email (email).
• Campaign drill-down shows welcome-flow-day-1.

Example 4: An influencer link

https://yourstore.com/?utm_source=jane-instagram&utm_medium=affiliate&utm_campaign=jane-launch-q1

• utm_medium=affiliate matches the Affiliate rule.
• Classified as Affiliate.
• Campaign drill-down shows jane-launch-q1. You can see Jane's performance specifically by filtering on utm_source=jane-instagram.

Example 5: An organic Instagram link in bio (no UTMs)

https://yourstore.com/products/new-drop
(Referrer: https://l.instagram.com/?u=https%3A%2F%2Fyourstore.com%2F...)

• No UTMs, no click IDs.
• Referrer domain is instagram.com → matches the Meta Organic referrer rule.
• Classified as Meta Organic (meta_organic).

Example 6: A Meta ad that contradicts itself

https://yourstore.com/?utm_source=meta&utm_medium=email&utm_campaign=oops

• utm_medium=email is NOT in the paid-medium list, so the Meta Paid rule (which requires both source AND medium to match) fails.
• The Email rule fires on utm_medium=email alone.
• Classified as Email (email). The utm_source=meta is ignored.
• This is the most common contradictory-combo mistake — see below.

Common mistakes

Missing utm_campaign

The visit still classifies into the right channel, but every report that groups by campaign collapses these orders into (no campaign). You lose the ability to compare "spring sale" against "winter clearance" within Meta. Easy fix; just tag it.

Typos in parameter names

utm_meduim (instead of utm_medium), utm_camapign, utm_soruce. These get silently ignored by Prism's classifier — the rule for "utm_medium contains paid" never sees the misspelled key, so it falls through. The traffic ends up classified by referrer (probably Referral or Direct) and you'll have no idea why your Meta spend looks like it's not driving anything.

Use a UTM builder template that copy-pastes a known-good URL, or a tool like Klaviyo's UTM Tracking settings that prevents typos by giving you dropdowns.

Tagging internal links

If a customer clicks an internal link on your site (say, a "Shop the Sale" button on your homepage) and that link has UTMs on it, the session restarts attribution. Prism sees the UTMs on the new page and treats it like a new visit from that source.

We see this most often when an internal navigation tile in a homepage hero is built with the same URL template as the marketing team uses for their Klaviyo emails — and the URL has ?utm_source=klaviyo&utm_medium=email baked in. The result: every customer who clicks that homepage tile gets re-attributed to email mid-journey.

Tagging your own domain in utm_source

?utm_source=yourstore.com&utm_medium=internal

Don't do this. We've seen merchants use their own domain in utm_source to track "newsletter signup popup → product page" navigation. The result: Prism's referrer fallback rule treats the traffic as Referral from your own domain, which inflates Referral and skews your channel mix.

If you want to track internal funnel steps, use an event tracker or a separate URL parameter that isn't utm_*.

Contradictory UTM combinations

The most common one is utm_source=meta + utm_medium=email, usually because someone copy-pasted a base URL and didn't update both fields. As shown in Example 6 above, the channel ends up as Email — utm_source is effectively ignored.

Other contradictions we've seen:

• utm_source=google&utm_medium=email (Google email blast?) → classifies as Email. The utm_medium=email rule wins.
• utm_source=email&utm_medium=cpc → classifies as Email. utm_source=email is enough to trigger the Email rule on its own, so the cpc medium is ignored.

The pattern in both: when a source or medium value matches an owned-channel rule (like Email), that rule fires and the rest of the URL stops mattering. Audit your URLs before launching a campaign. If you'd want a person reading the URL to interpret it the same way Prism does, you're probably fine.

Auto-tagging on top of manual tagging

If you set utm_source=google&utm_medium=cpc manually AND Google auto-tagging is on, you'll get both UTMs and gclid on the same URL. The click ID wins (it's higher priority), so the manual UTMs get ignored — but utm_campaign still flows through for campaign drill-down. No harm done, just be aware that your manual utm_source value isn't actually doing anything.

Verifying your UTMs in Prism

After you set up tagging on a campaign, the fastest way to verify is to:

1. Click your own ad (or send yourself the email) from a private/incognito window. Use your phone if you don't want to mess with browser sessions on desktop.
2. Land on your site, click around a bit, maybe add something to cart.
3. Wait 2–3 minutes.
4. Open Prism → Attribution → filter by today's date.
5. You should see a session attributed to the channel you expected.

For deeper verification, open the Customer Journey Sankey diagram and look at the most recent paths. You should see your test visit's channel as one of the entry points.

If a click is showing up as the wrong channel:

• Check the URL parameters in your browser's address bar after you land on your site (sometimes ad platforms strip or rewrite them).
• Cross-check the priority order in the How Prism classifies channels section. Click IDs always win.
• Look for typos in the parameter names.
• If you're auto-tagged by Google or another platform, the platform's tag may be overriding what you set manually.

When to ask for help

If you've gone through this guide and your channels still don't look right, email hello@theprismapp.com with:

• A specific example URL that's classifying wrong
• The channel you expected it to be
• The channel Prism actually shows

We'll trace it through the classifier and tell you what happened. If the issue is on Prism's side, we fix it. If it's a tagging mistake, we'll show you exactly what to change.