A subdirectory structure, in the context of international SEO, refers to organizing country or language-specific versions of a website within folders under a single domain — for example, example.com/uk/ or example.com/es/ — rather than using separate domains for each market.
This approach is generally considered the most SEO-efficient option for most businesses expanding internationally, since it consolidates domain authority under one root domain rather than splitting it across multiple ccTLDs or subdomains.
A subdirectory approach still requires proper hreflang implementation to ensure search engines serve the correct language or regional version to the right audience, and clear internal linking between versions for a good user experience.
We help structure international subdirectories correctly as part of our Technical SEO service.