What each UTM parameter does
When someone clicks a tagged link, Google Analytics 4 reads the parameters and saves them with the visit. Google describes them in its help page on URL builders:
- utm_source: the referrer, such as google, newsletter or a billboard.
- utm_medium: the marketing medium, such as email, cpc or banner.
- utm_campaign: the product, slogan or promo code, such as spring_sale.
- utm_term: the paid keyword.
- utm_content: tells creatives apart, such as two buttons in the same email.
- utm_id: the campaign ID, the same one you use if you upload campaign data.
Google recommends always using utm_source, utm_medium and utm_campaign. A missing parameter shows as (not set) in your reports.
How source and medium decide the channel
GA4 sorts visits into a default channel group using rules for source and medium. Some of Google's rules:
- Email: the source or medium is email, e-mail, e_mail or e mail.
- Organic Social: the source is a known social site, or the medium is social, social-network, social-media, sm, social network or social media.
- Paid Social: the source is a social site and the medium contains cp (such as cpc), is ppc or retargeting, or starts with paid.
- SMS: the source or medium is exactly sms.
- Paid Search: the source is a search site and the medium is paid in the same way, such as cpc.
When no rule matches, the visit is Unassigned. That is the case for medium qr, because there is no QR channel. You can sort that traffic yourself with a custom channel group. The presets above follow these rules. The Facebook, Instagram and LinkedIn presets use medium social, which counts as organic. For paid ads, change the medium to cpc or paid_social.
Google Ads can tag links for you with auto-tagging, and Google says that in GA4 auto-tagging takes priority over manual UTM tags.
Naming conventions that keep reports clean
- Use lowercase. Google says values are case sensitive: utm_source=google and utm_source=Google are different values. One capital letter splits a channel into two rows, and the numbers no longer add up.
- Pick one separator. Use hyphens or underscores, not spaces. A space turns into %20 and is easy to type differently next time.
- Keep a shared list. Write down the sources and mediums your team uses, such as newsletter, email, facebook, social, store and qr, and reuse them in every campaign.
- Name campaigns so they sort. A name like 2026-summer-scratchcard sorts by year and is easy to find.
Track a campaign from link to sign-up
Put a tagged link in every channel that promotes your campaign: the newsletter, the SMS, the social post and the QR code in your shop. Then you can see which channel brought the visits. Read how to announce a competition across channels, and which marketing KPIs to follow. In Scratcher, campaign analytics shows visits, players, sign-ups and winners for each campaign, and which channels brought people in.
