Hey, the author of the benchmark here.

The benchmark data was prepared in April 2026 (when I was manually doing our VAT return with my co-founder). The invoices were indeed found manually.

Currently we're using a custom "invoice searcher" built on Kimi 2.6 (in our testing several weeks ago it outperformed Opus 4.7; it was just more persistent).

Ultimately, I still verify everything manually after the model is finished fetching invoices for the month -- but it's a great help to have all the invoices already found (usually correctly).