Bilingual hreflang implementation for Canadian sites is one of the most commonly botched technical SEO tasks. Done correctly, it directs Google to serve the right language version to the right audience based on browser language, IP location, and Google interface settings. Done wrong, it suppresses one or both language versions from search results entirely. The correct setup for an EN/FR Canadian site: every page in both languages includes hreflang tags identifying all language versions including itself. Use either link tags in the HTML head, HTTP headers, or XML sitemap entries — pick one method and use it consistently. The minimum tag set per page: hreflang='en-CA' pointing to the English Canadian URL, hreflang='fr-CA' pointing to the French Canadian URL, and hreflang='x-default' pointing to whichever version should serve as fallback for unmatched users (typically the English version for Canadian-domiciled sites). Reciprocal hreflang is mandatory. Page A must reference Page B, and Page B must reference Page A. If only Page A points to Page B, Google ignores the relationship and may treat the pages as unrelated duplicates. Audit reciprocity quarterly using Screaming Frog or Sitebulb's hreflang audit reports. Language codes matter. Use 'en-CA' (English Canada) and 'fr-CA' (French Canada), not 'en' and 'fr'. The country qualifier signals to Google that these versions specifically target Canadian audiences, distinguishing them from US English ('en-US') or French French ('fr-FR'). For sites targeting both Quebec and France French audiences, you can use both 'fr-CA' and 'fr-FR' versions, but they must point to genuinely different content adapted for each audience. Common mistakes we see in Canadian client audits: using 'fr' alone when the content is Quebec French (causes Google to default-serve to France French audiences instead); pointing hreflang to URLs that 301-redirect (Google ignores the relationship); using inconsistent URL formats with and without trailing slashes; and forgetting to update hreflang when URLs change during a redesign. Each of these silently suppresses bilingual visibility.