Account Invoice Tax - Computation By Column

-Invoice taxes:

legend:

TA(l) TaxAmount for line l TBA(l) TaxBaseAmount for line l TA(t) TaxAmount for tax t TBA(t) TaxBaseAmount for tax t

default behaviour:

openerp by default calculates taxes line by line as a function of line tax base amount and then groups these amounts by tax. TA(l) = f(TBA(l) TA(t) = sum( round( TA(l) ) ) /sum on lines l to which tax t is applied

this module behaviour:

In Italy the correct way to compute taxes is to first compute the tax base amount TBA(t) and the compute TA as a function of TBA(t) TBA(t) = sum( TBA(t) ) /sum on lines l to which tax t is applied TA(t) = f( TBA(t) )

the result difference is small but important