Country rules with visible sources
Tax references are stored per country with effective dates and source notes. Rules that need source review are flagged in the country guide and tax calendar; confirm current obligations with your authority before filing. Earlier periods keep the rule version used when the return was prepared.
Work with your accountant, not around them
Your accountant can review a return, add adjustments and approve it from their own login. Every adjustment is kept with a note, so the return explains itself at audit time.