Use this when the user has job offers or candidates in 2 to 6 countries, each with its own gross salary (in USD or the local currency), and wants the total employer cost of each (e.g. "candidate A in Poland at 240,000 PLN, candidate B in Portugal at 45k: what does each cost the company?"). A monthly offer is passed with salary_period "month", which applies each country's statutory 13th or 14th month (e.g. "un candidat à 3 000 par mois à Madrid et un autre à 60 000 par an à Dublin"). Returns salary plus statutory employer charges, before any Employer of Record fee, the difference and ratio of each total to the smallest one, and the contribution ceilings each salary reaches. Rows come back in the order given. Do not use when the salary is the same in every country (use compare_countries). Data snapshot 2026-10-11. Cost comparison, not legal or tax advice.