The five tags
- utm_source is where it came from. instagram, newsletter, partner-site.
- utm_medium is the kind of channel. social, email, cpc, qr, print.
- utm_campaign is which push it belongs to. spring-sale, launch-2026.
- utm_term is the keyword, mostly used in paid search.
- utm_content is which version, when you have two of the same thing. header-link and footer-link, or image-a and image-b.
Source, medium and campaign are the three that earn their keep. The other two are for when you need to tell two nearly identical things apart.
Naming is the whole job
The parameters are trivial. The discipline is not, and the failure mode is always the same: six months of data split across Instagram, instagram, IG and insta, none of which add up in the report.
Three rules prevent nearly all of it.
- Lowercase everything. Analytics treats Email and email as different values.
- Use hyphens rather than spaces or underscores, consistently.
- Write the naming rules down somewhere the whole team can see, before the first campaign rather than after the third.
If more than one person builds links, keep a shared list of allowed values for source and medium. It is dull and it saves the reporting.
The distinction people get wrong
Source is the specific place. Medium is the category of place. instagram is a source, social is a medium.
Putting instagram in both fields is the most common mistake, and it makes the medium report useless because every row is a different platform rather than a channel type.
The test: if you added a second social network tomorrow, would it share the medium value? If yes, you have the medium right.
How this works with a short link
Two approaches, and they solve different problems.
You can append the parameters to the short link itself, which means anyone copying the link keeps them. You can also store them on the link so they are added at the redirect, which means nobody can accidentally strip them and the shared address stays clean.
The second is better for anything printed or spoken, because short.bi/spring stays short while still arriving at the destination fully tagged.
Whichever you choose, verify once. Send yourself through the link and check that the campaign appears in your analytics. It either works permanently or it never worked at all, and finding out which takes two minutes.
Tagging things that are not online
A leaflet has no referrer. Neither does a poster, a radio mention or a business card. Analytics will file all of it under direct, which tells you nothing.
A tagged short link fixes that. Give the leaflet utm_medium=print and utm_source=leaflet-march, put the code on the artwork, and the visits arrive labelled.
This is the single most useful thing UTM parameters do for a small business, and it is the use most guides skip entirely.
When to leave them off
Internal links on your own site should never carry UTM parameters. They overwrite the original source, so a visitor who arrived from a newsletter and then clicked a tagged internal link is recorded as coming from the internal link instead.
They are also worth leaving off anything you expect people to share by hand. A parameter written for one channel travels with the copy into another and quietly poisons the report.
Tag what you distribute yourself. Leave the rest alone.