Count the carriers a group across fifteen countries actually pays. Then count the products: fixed data, mobile, voice, hosting, and usually a legacy line nobody will admit to. Then count the layouts, because a single carrier commonly issues a different document for each product line, and a different one again after a billing-system migration.
Our estimate from that count, not a survey: 40–80 invoice formats across 15 countries for a group of this shape. Carriers change layouts on their own schedule, and the first sign is usually a column that has quietly moved.
So uncertainty is declared rather than smoothed over, and some of it lands in a queue on purpose.



