Use official sources
We record the authority, effective date and exact section or table behind each rate.
Test real situations
We test both sides of every slab boundary, unsupported cases and representative examples.
Show what may change
Results separate known rates, your assumptions and charges that could not be included safely.
Rounding
Money is calculated as integer paisa where practical. The interface may round a headline to whole rupees, while detailed lines preserve exact paisa when it affects reconciliation.
Corrections
When someone reports a problem, we check it against primary evidence and add a test before changing the calculation.