Does Excel count as open source and industry standard? Because if so, the UK has a giant tax spreadsheet you can put your data in and get tax owed: https://asse

Does Excel count as open source and industry standard? Because if so, the UK has a giant tax spreadsheet you can put your data in and get tax owed: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1044764/2022-tcg.zip https://assets.publishing.service.gov.uk/government/uploads/... This document is the source of truth for tax calculations so it'll always give you the right answer.