The link a marketing partner gave me already has a utm_source. Should I replace their values with mine or keep them?
If you will publish the link in your own campaign, replace the old values so the visit is credited to your source. If the partner needs their tags to measure their own results, keep them and add only what is missing. Either way, do not type your parameters onto the end by hand, because that makes a link with utm_source twice. The builder spots existing tags, lets you choose, then shows what happened to each parameter.
The trouble with a tag that appears twice
Take the partner's link and add &utm_source=newsletter to the end by hand, and the link now holds two values for the same parameter. Analytics tools do not agree on how to handle that, and one may simply take one value without telling you which. You end up with numbers you cannot attribute. The fix is a final link with one value per parameter, and you choosing which.
The example: a partner link with source and medium
A marketing partner sent you this link to the oud page:
https://example.com/oud?utm_source=partner&utm_medium=referral
Paste it into the UTM campaign link builder and a note says the URL already contains utm_source=partner and utm_medium=referral, with a choice between Replace existing and Keep existing. We entered source newsletter, medium email and campaign eid to send it in the newsletter.
Option one: Replace existing (the default)
https://example.com/oud?utm_source=newsletter&utm_medium=email&utm_campaign=eid
Your values took the place of the old ones and nothing is duplicated. The parameter table shows source and medium as Replaced and campaign as Added. Choose this when the link goes out on your own channel and you want the visits counted there.
Option two: Keep existing
https://example.com/oud?utm_source=partner&utm_medium=referral&utm_campaign=eid
partner and referral stayed, and the campaign eid was added because it was not there before. The table shows source and medium as Existing kept, each with a note that your values newsletter and email were ignored. Choose this when the partner is the one publishing the link and you only want to add a campaign name for your own sorting.
Deciding quickly
- Who will publish the link? If you, replace. If the partner, keep their tags.
- Do you pay the partner commission based on their visits? Do not replace their tags before asking; they may rely on them for their reports.
- Is it an old link copied from a finished campaign? Replace, or the old values will blend the two campaigns.
Any other parameters in the link, such as a product ID or referral code, stay where they are, untouched. If you need to see how a value is written inside a link, or decode one to read it, use the URL encoder/decoder.
Common questions
Does the tool remove partner tags I did not give a value for?
No. Any existing utm parameter you left empty stays as it is and appears in the table as Already present.
Does the choice apply to all parameters at once?
Yes, it is one choice for every clashing parameter. Anything that does not clash is always added.