A URL mismatch means that for a keyword the wrong page of the website ranks instead of the intended target URL. It is especially critical when an info page appears instead of a commercial landing page.
A URL mismatch occurs when Google shows a different URL for a than the one that should rank. For example, an explanatory blog article ranks even though a commercial service page is the intended target.
Possible consequences are:
fewer leads and weaker conversion,
unclear user journeys,
unstable rankings,
diluted signals.
To diagnose it, compare the defined target URL with the URL actually ranking, check the of the current , and review the data per URL in Google Search Console. Often it helps to point internal links and consistently to the target page and to sharpen its on-page signals such as title and . Sometimes, though, it is not Google that is wrong but the target URL: if the ranking page fits the search intent better, the targeting strategy should be adjusted.