What if an SEO company creates duplicate content?
Treat it as a defect in the company’s work, and find out which kind of duplication it is before choosing the fix. Some duplication is technical: the same page reachable at several URLs, which Google handles by choosing one version to show. Pages mass-produced from a template, differing only in a city name or a few swapped words, are a different problem, because they can fall under Google’s spam policies. The first kind is fixed with redirects and canonical tags; the second needs the pages rewritten or removed. In both cases the cleanup is work the company owes you, not a new project.
Which kind of duplication you have
Google’s page on how canonicalization works is plain about the first kind: “Some duplicate content on a site is normal and it’s not a violation of Google’s spam policies.” When Google finds pages that seem the same, it groups them and chooses one as the canonical, the version it shows in search results, and it crawls the duplicates less frequently. This kind is not a spam violation, but the page Google chooses may not be the one you paid to have built.
The second kind comes from how the pages were produced: location pages that differ only by the city name, one article rewritten into a set of near-identical versions, or bulk pages generated from the same template. Google’s spam policies define scaled content abuse by purpose, as many pages generated mainly to manipulate rankings rather than to help users, whatever tool produced them. A canonical tag does not change what those pages are; the pages themselves have to change.
Finding the affected pages
Search Console’s Page indexing report lists duplicates under their own reasons. For a page listed as a duplicate without a user-selected canonical, the report explains that “Google has chosen the other page as the canonical for this page, and so will not serve this page in Search.” The URL Inspection tool shows which URL Google selected for any single page.
To find copies the report does not group together, take a distinctive sentence from one of the new pages and search for it inside quotation marks with the site: operator and your domain, both described in Google’s help page on refining web searches. The results show which indexed pages on your site Google matches to that exact wording. Keep the affected URLs in one list with the date you found them; you will need it for the fix and for the conversation with the company.
Choosing the fix
Google’s guide to specifying a canonical URL lists the methods in order of how strongly they influence the choice: redirects and rel=”canonical” annotations are strong signals, and listing a URL in a sitemap is a weak one. The methods can be combined, which strengthens the preference.
A permanent redirect suits a duplicate that is being retired; the guide’s comparison of methods says of redirects: “Use this only when deprecating a duplicate page.” A rel=”canonical” link suits a duplicate that has to stay available to visitors, and internal links should point to the version you want shown. Neither is an instruction Google must follow. Its canonicalization page says that “indicating a canonical preference is a hint, not a rule.” Two shortcuts appear on the guide’s list of what not to do: blocking duplicates in robots.txt, and using the URL removal tool, of which it says: “It hides all versions of a URL from Search.”
Template pages with nothing distinct need a different answer. Redirecting or canonicalizing them tidies the index, but it gives a reader no reason to visit them. Either rewrite each page around what is actually different about it, such as the details of that service area, or remove the pages and redirect their URLs to the page that covers the topic.
Holding the company to the cleanup
Send the company your dated list of affected URLs and ask for three things in writing: how the duplication happened, the fix for each group of pages (redirect, canonical tag, rewrite, or removal), and confirmation that the work is done at no charge, since it corrects the company’s own output. Ask what will change in its process so the pattern does not return. After the changes, use the URL Inspection tool on the pages you kept to see whether Google now selects them as canonical.
This is general information, not legal advice. If the company disputes its responsibility, a lawyer can review the agreement and the record of affected pages with you.