MSCLKID
MSCLKID stands for Microsoft Click ID. It is a unique code that Microsoft Advertising adds to your landing page URL each time someone clicks an ad, through a feature called auto-tagging. The msclkid lets Microsoft match that exact click to later activity, such as a conversion tracked by the UET tag.
Why MSCLKID Matters
MSCLKID is how Microsoft Advertising ties a click to a conversion. When auto-tagging is on, Microsoft appends an msclkid to every ad click on the Microsoft Search Network, which includes Bing, Yahoo, and AOL. The Universal Event Tracking (UET) tag on your site reads that value and links the visit to the ad that drove it.
The msclkid also enables offline conversion import. If a click becomes a sale in your CRM, you upload the stored msclkid with the conversion. Microsoft then credits the exact click that started the journey. This feeds automated bidding strategies, which use real conversion data to set bids. Clicks must be imported within 90 days for the match to work.
Like Google’s GCLID, the msclkid appears only on paid ad clicks, not on organic links. That is the key difference from Meta’s FBCLID, which is added to both.
How MSCLKID Works
The process runs automatically once auto-tagging is enabled:
- A user clicks a Microsoft ad. Microsoft appends an msclkid to the destination URL.
- The landing page loads. The UET tag reads the msclkid and stores it in the
_uetmsclkidfirst-party cookie, which lasts about 90 days. - The user converts. The msclkid is captured with the conversion or passed into a form and your CRM.
- Microsoft receives the msclkid through UET or offline import and matches it to the original click.
An msclkid-tagged URL looks like this:
https://linkutm.com/?msclkid=a1b2c3d4e5f6g7h8
MSCLKID vs UTM
An msclkid and a UTM are not the same thing. A UTM is readable text you write yourself, like utm_source=bing&utm_medium=cpc. GA4 reads UTMs to classify traffic from any channel. An msclkid is an opaque code Microsoft generates and reads to track conversions and optimize bids.
| MSCLKID | UTM | |
|---|---|---|
| Created by | Microsoft Advertising, automatically | Marketer, manually |
| Read by | Microsoft Advertising (UET) | GA4 and analytics tools |
| Readable | No (random string) | Yes (plain words) |
| Scope | Microsoft Advertising only | Any channel |
For Microsoft Advertising, auto-tagging with msclkid handles conversion tracking. For other channels like email or social, you still need UTM parameters. MSCLKID is one specific type of click ID; Google uses GCLID and Meta uses FBCLID.
How to Find or Enable MSCLKID
Click one of your own Microsoft ads and look at the URL in the address bar. If you see msclkid= followed by a string, auto-tagging is working. If it is missing, enable it in Microsoft Advertising under Settings, then Account level options, by turning on auto-tagging of the UET tag. Most accounts have it on by default.
Frequently Asked Questions
What does MSCLKID stand for?
MSCLKID stands for Microsoft Click ID, sometimes called the Bing Click ID. Microsoft Advertising adds it to landing page URLs through auto-tagging. It uniquely identifies a single ad click.
What is the difference between msclkid and UTM?
MSCLKID is generated automatically by Microsoft and read by the UET tag to track conversions and optimize bids. A UTM is written manually and read by GA4 to label traffic from any channel. The msclkid is a random string; a UTM uses readable words.
How long does an msclkid last?
The _uetmsclkid cookie that stores the msclkid lasts about 90 days by default. For offline conversion import, you must upload the msclkid to Microsoft within 90 days of the click.
Is msclkid the same as the Bing Click ID?
Yes. MSCLKID is the official name, but many marketers call it the Bing Click ID because Microsoft Advertising was formerly Bing Ads. Both refer to the same auto-tagged click parameter.
To tag campaigns on channels that auto-tagging does not cover, build clean links with the free UTM builder at linkutm.