Short answer
Fix a short list of allowed utm_source and utm_medium values and make them match GA4's channel rules: mediums like cpc or paid-social for paid clicks, display for banners, email for email, social for organic posts. Use lowercase and hyphens only. Give ChatGPT ads their own source, such as chatgpt-ads, so paid clicks don't merge with organic chatgpt.com links, and put the campaign and the buyer question in utm_campaign and utm_content.
Allowed values
| Channel | utm_source | utm_medium | GA4 default channel |
|---|---|---|---|
| ChatGPT ads | chatgpt-ads | cpc | Paid Other (give it a custom channel) |
| LinkedIn ads | paid-social | Paid Social | |
| Microsoft Ads | bing | cpc | Paid Search |
| Google Ads | cpc (or auto-tagging) | Paid Search | |
| Programmatic display | dsp name, e.g. dv360 | display | Display |
| Newsletter | newsletter | ||
| Organic LinkedIn posts | social | Organic Social |
How GA4 sorts them
- Paid Social: a social source and a medium matching
^(.*cp.*|ppc|retargeting|paid.*)$. - Paid Search: a search engine source with the same paid medium pattern. That's why Microsoft clicks should use bing.
- Display: medium display, banner, expandable, interstitial or cpm.
- Paid Other: a paid medium with a source GA4 doesn't recognise, which is where chatgpt-ads lands.
- AI Assistant: GA4's default group now sends visits from assistants such as ChatGPT, Gemini and Copilot here; organic AI traffic, not your tagged ads.
Standard GA4 properties can have two custom channel groups. In one of them, add an AI assistants channel built with the GA4 AI traffic regex and a ChatGPT ads channel for utm_source=chatgpt-ads, both placed above Referral and Paid Other.
Campaign, content and term
| Parameter | Holds | Example |
|---|---|---|
| utm_campaign | The campaign name, same parts as in the platform | 2026q4_linkedin_abm_tier1_uk |
| utm_content | The ad, or for ChatGPT ads the buyer question | close-netsuite |
| utm_term | Variant or keyword | v2 |
Build names with the campaign naming generator, and see our ChatGPT ads convention.
Governance in four rules
- Lowercase, hyphens inside values, no spaces.
- Only values from the shared list; new values need the owner's approval.
- Every link built in the UTM builder or a template sheet, never by hand.
- No UTMs on internal links; they overwrite the original source.
Questions
Which utm_medium puts traffic in Paid Social in GA4?
A social source plus a medium matching GA4's paid pattern, such as cpc, ppc, retargeting or anything starting with paid, for example paid-social.
Why not use utm_source=chatgpt.com for ChatGPT ads?
Organic links from ChatGPT often already arrive as chatgpt.com. A distinct source such as chatgpt-ads keeps paid and organic apart.
Do UTMs work with Google Ads auto-tagging?
GA4 uses the gclid for Google Ads data when auto-tagging is on. Manual UTMs are mainly for other platforms.
Who should own the taxonomy?
One person in marketing operations, with a shared sheet of allowed values and a builder everyone uses.
Facts checked against the sources below on 19 October 2026. Ad platforms change quickly: if something here no longer matches what you see, tell us and we will update it.
