What ttclid actually is
ttclid is the TikTok Click Identifier, appended automatically when someone clicks a TikTok ad. Like Meta's fbclid and Google's gclid, it is generated per click and exists so conversions on the destination site can be matched back to the ad that produced them, including through TikTok's server-side events.
Not the same thing as TikTok's macros
TikTok advertisers also work with dynamic macros, which look nothing like ttclid and serve a different purpose. Macros such as __CAMPAIGN_NAME__, __AID__ and __CID__ are placeholders you type into your URL, and TikTok swaps in real values at click time so they can populate your UTM parameters.
They are worth naming carefully because the two most useful ones are misleadingly named: __AID__ is the ad group ID, not the ad ID, and __CID__ is the creative ID, not the campaign ID. Wire them into the wrong slots and every report downstream is confidently wrong. The tables in our UTM builder spell out what each one resolves to, so you can copy the pairing instead of guessing it.
Is it safe to remove?
For a visitor, yes. For the advertiser it is the link between spend and result, so it should survive every hop between the ad and the landing page. If it does not, a redirect in the middle is probably discarding query parameters.