A hreflang return tag refers to the requirement that hreflang implementation must be reciprocal — if Page A links to Page B via hreflang, Page B must also link back to Page A (and to every other version) for the markup to be considered valid by search engines.
Missing or broken return tags are one of the most common hreflang implementation errors, often causing search engines to ignore the hreflang markup entirely, even when the rest of the implementation is otherwise correct.
Regularly auditing hreflang implementation across all language and regional versions of a site helps catch broken return tag relationships before they undermine international SEO performance.
Hreflang auditing is part of our international Technical SEO service.