What is a UTM naming convention?

A UTM naming convention is a documented set of rules for how you write UTM values, so the same campaign, source, and medium are always tagged the same way. It is what stops one channel from showing up as facebook, Facebook, and fb across three separate lines in your reports.

Should UTM values be uppercase or lowercase?

Lowercase, every time. UTM values are case-sensitive, so Email and email are counted separately. Lowercase is the common convention because it is the hardest to get wrong; the exact choice matters less than picking one and never deviating.

Hyphens or underscores in UTM values?

Either works, but pick one and use it everywhere. Avoid spaces entirely, because a space is encoded as %20 in the URL and reads badly in reports. A hyphen (spring-sale) is the most common choice.

Do I need a spreadsheet to track UTMs?

For a team, yes, a shared sheet listing the agreed source, medium, and campaign values prevents drift. For one person, the discipline matters more than the tool: decide your values, write them down once, and reuse them rather than inventing a new spelling each time.

UTM naming conventions that stay clean

UTM naming conventions that don't turn into a mess.

A UTM naming convention is a documented set of rules for how you write UTM values, so the same campaign is always tagged the same way. Get it right and your reports stay readable. Get it wrong and one channel quietly splits into five spellings of itself. The rules are short.

Glen Johnston Founder, Lead Source · 4 min read Published 2 June 2026

Why a convention matters at all

UTM values are free text. Nothing validates them. Whatever you type becomes a row in your analytics, exactly as typed. That is the whole problem: facebook, Facebook, and fb are three different sources to your analytics, so one channel's results get scattered across three lines and none of them shows the real total. Multiply that across a year of campaigns tagged by three different people in a hurry, and the report becomes fiction.

A naming convention is the fix, and it is unglamorous: agree how you spell things, write it down, and stick to it.

The four rules that do most of the work

Lowercase, always. UTM values are case-sensitive, so Email and email are counted separately. Lowercase is the convention because it is the hardest to fumble.
One separator, never spaces. A space becomes %20 in the URL and looks broken in reports. Pick a hyphen (spring-sale) or an underscore and use it everywhere.
A fixed vocabulary for source and medium. These two should come from a short, closed list, not your imagination. medium is cpc, email, social, referral, and little else. If you allow ppc one week and cpc the next, you have two mediums for one thing.
Write it down somewhere shared. A convention that lives in one person's head is not a convention. A one-tab spreadsheet of approved values is enough.

A starter convention you can copy

This is a sane default. Adjust the vocabulary, keep the structure:

utm_source: the specific platform, lowercase. google, bing, linkedin, newsletter.
utm_medium: from a fixed list only. cpc, email, social, referral, display.
utm_campaign: a short, dated slug. 2026-q2-spring-sale sorts and groups cleanly.
utm_content: the variant, when you are testing two links. header vs footer, variant-a vs variant-b.

Once the convention is set, the fastest way to apply it consistently is to stop typing query strings by hand. Our free UTM builder lays the fields out so you fill them the same way every time, and it encodes the values correctly on the way out.

The mistake a convention can't fix

Even a perfect convention only makes your analytics tidy. It does not carry the source into your CRM or tell you which tagged campaign produced a paying customer, because the UTM lives in the URL and your CRM rarely keeps it. That is a different job. The background on it is in the UTM tracking guide, and the fix is lead source tracking.