Why files work best
Carrier billing APIs are the integration everybody assumes exists. For a group of this shape, a handful of operators publish one, and each of those gates it behind an account relationship that needs your permission and your credentials.
So the first bill path is file-based, and the parser is the moat and the treadmill. Our estimate, with the working in the article on invoice formats: 40–80 invoice formats across 15 countries for a group of this shape, and carriers revise them. A new format starts from three invoices, and the status label on each path says where it stands.
Matched on evidence
Carrier names on invoices are inconsistent, transliterated, abbreviated and bilingual. Matching runs through normalisation and a synonym list rather than string equality, and a low-confidence match opens a review item rather than quietly creating a new carrier.
The catalogue is current-state: merged and dissolved operators are removed rather than kept as history, and known misclassifications are corrected explicitly. It is a reference index, and your own carriers are whichever of them your invoices name.




