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# Why are some calls showing an unknown source?

* Calls labelled **unknown source** are calls that Nimbata could not attribute to a tracked marketing source or session. 
* This classification describes the result of attribution, not the cause. 
* Several different scenarios can produce it.
* The most common cause is a caller dialing the tracking number directly.

E.g. Entering it manually, calling from a printed list or brochure, or using the number outside of a tracked environment. 
Unknown source can also occur whenever attribution data is simply unavailable at the time the call is placed.

# What to check

### Verify how the tracking number is being displayed

* Make sure your tracking numbers are only shown dynamically via your website or in tagged materials where source data can be captured. 
* If the number appears anywhere else, on printed materials, saved in a contact list, or shared outside tracked pages, callers may dial it directly and no source information will be sent.

### Review your dynamic number insertion setup

* If you expect calls to be attributed to tracked channels (UTM tags, campaign links, ad sources), confirm that the DNI script is installed correctly on every page you want to track. 
* An incorrect or incomplete DNI setup results in calls landing without source attribution.
* Calls with an unknown source do not necessarily indicate a problem with your tracking numbers. 
* They reflect calls that could not be mapped to a known marketing source based on how the call originated.
* If you're seeing a higher-than-expected number of unknown source calls, reviewing how and where your tracking numbers are displayed is the right first step.
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Detailed guide: [**DNI script 101: how to install and configure it**](https://help.nimbata.com/en/article/dni-script-101-how-to-install-and-configure-it-1l7zt51/) 
Detailed guide: [**Why are numbers not swapping on my website?**](https://help.nimbata.com/en/article/why-are-numbers-not-swapping-on-my-website-dfo4sa/) 
Troubleshooting: [**Setup looks correct but no calls yet: what to check**](https://help.nimbata.com/en/article/setup-looks-correct-but-no-calls-yet-what-to-check-1s1bwkh/)