International AEO: how to optimise for AI citations across 35 global domains

The international AEO challenge

Single-domain AEO is relatively straightforward: one language, one audience, one set of crawl permissions. International AEO, managing visibility across multiple country domains, language variants, and regional AI systems, introduces a layer of complexity that most SEO guides do not address.

Challenge 1, Regional llms.txt coverage

llms.txt files need to exist at the root of each country domain independently. A file at yourdomain.com/llms.txt does not apply to fr.yourdomain.com or yourdomain.de. Each domain requires its own file, in the correct language, with region-appropriate contact details.

We found that only 4 of 35 domains had llms.txt files. The remaining 31 were unconfigured, meaning AI systems had no explicit crawl guidance.

Fix: Created a templated llms.txt generation process that produced a localised file for each domain, with the Description field written in the domain's primary language.

Challenge 2, BLUF applied in English only

The English-language domain had been BLUF-optimised. Every other language variant still opened with brand narrative. Since LLMs weight the first paragraph so heavily, non-English pages were being skipped by retrieval systems even when the rest of the content was high quality.

Fix: Used the BLUF templates from the NotionCue resource library as a framework, translated by native speakers for each region. Direct translation of English BLUF often fails, native rewriting is required.

Challenge 3, hreflang and AI retrieval

hreflang is a traditional SEO signal for Google to understand language targeting. AI systems queried in a specific language use language detection on the content itself, pages that mix languages or have incorrect lang attributes in the HTML head score lower.

Results

After implementing llms.txt on all 35 domains, rewriting BLUF intros in all primary languages, and fixing HTML lang attributes: average AEO score across all domains rose from 29 to 61 in 60 days. AI-referred traffic across the domain portfolio increased by 218%.