Tag a link you send on WhatsApp with utm_source=whatsapp and utm_medium=social. Google's source list includes whatsapp as a social site, so the visit lands in Organic Social. Tags belong on the link to your site: a wa.me link opens a chat, and the only parameter WhatsApp documents for it is the message text.
The interactive UTM builder loads with this page, pre-filled for WhatsApp, and runs entirely in your browser.
Google classes whatsapp and whatsapp.com as social sites, and a medium of social qualifies for Organic Social by itself, so either half of this tag would get there alone.
Where to put it
Chats and groups: send the tagged URL as part of your message.
Share buttons: put the tagged URL inside a wa.me link's text parameter, https://wa.me/?text= followed by the URL-encoded message.
Encode the whole message, tagged link included, so its ampersands don't cut the tags off.
Chat buttons to your own number use https://wa.me/ and the full number in international format, without zeros, brackets or dashes. UTMs on that link go nowhere.
Click-to-WhatsApp ads: attribution runs through ctwa_clid and Meta's Conversions API, not UTMs.
Someone taps a share-on-WhatsApp button on your product page, picks a friend and sends. When the friend taps the link, whether that visit tells your analytics anything depends on what was inside the message. WhatsApp's share format is https://wa.me/?text= followed by URL-encoded text: the tap shows a list of contacts, and the text appears in the chat ready to send. If the link in that text carries utm_source=whatsapp&utm_medium=social, the friend's visit arrives tagged. If not, it arrives with whatever WhatsApp passes along, which WhatsApp doesn't document.
Encode the tagged link inside the text. WhatsApp asks for the text value URL-encoded, and that includes the link inside it. Leave the ampersands in your tagged URL raw and the first one ends the text parameter, so the chat receives your link with utm_source and nothing after it. Encode the full message in the URL encoder, then test on a phone by tapping the link that lands in the chat.
A wa.me chat link can't carry your tags. A link like https://wa.me/1XXXXXXXXXX opens WhatsApp, not your website, so UTMs added to it never reach GA4. The only parameter WhatsApp's help documents for these links is text, for the pre-filled message. To count taps on a chat button, count clicks on the link itself, for example by pointing the button at a tracked short link that forwards to the wa.me address. The click-to-chat link generator builds the wa.me part and shows the number it will dial.
Click-to-WhatsApp ads use a different ID. When a chat starts from a Click-to-WhatsApp ad, Meta hands the business a click ID, ctwa_clid, in the referral details of the incoming message's webhook rather than in a URL. To credit a sale to the ad, you store that ID with the conversation and send it back through the Conversions API. UTMs play no part, because no web page loads.
Social beats referral here. GA4 already recognises WhatsApp: Google's source list files both whatsapp and whatsapp.com under social. With a source of whatsapp, the Organic Social rule matches before GA4 reaches its Referral rule, so a medium of referral wouldn't give you a Referral row anyway. Use social, and both halves of the tag say the same thing. Why is my traffic showing as direct covers what happens to shared links that carry no tags at all.
Questions
How do I track a UTM link?
Add utm_source, utm_medium and utm_campaign to the link to your site, share it, and read the values in GA4's Traffic acquisition report. For WhatsApp, put utm_source=whatsapp&utm_medium=social on the link you paste into the chat, not on a wa.me link.
Why is my WhatsApp UTM tracking not working?
Three usual causes: the tags are on a wa.me link, which opens WhatsApp instead of your site; a tagged link inside a share link's text wasn't URL-encoded, so the first ampersand cut the tags off; or the source was typed as WhatsApp in some links and whatsapp in others, which GA4 reports as two values.
Do UTM parameters work on a wa.me link?
You can type them, but they do nothing useful. WhatsApp documents only the text parameter for wa.me links, and the tap opens WhatsApp rather than a page with your analytics on it.