optionally round tax to the nearest cent for each line item, #39487

1 files changed, 26 insertions, 2 deletions

diff --git a/FS/FS/TaxEngine/internal.pm b/FS/FS/TaxEngine/internal.pm
index f45bc08..d2a5d7f 100644
--- a/FS/FS/TaxEngine/internal.pm
+++ b/FS/FS/TaxEngine/internal.pm
@@ -3,6 +3,12 @@ package FS::TaxEngine::internal;
 use strict;
 use base 'FS::TaxEngine';
 use FS::Record qw(dbh qsearch qsearchs);
+use FS::Conf;
+use vars qw( $conf );
+
+FS::UID->install_callback(sub {
+    $conf = FS::Conf->new;
+});
 
 =head1 SUMMARY
 
@@ -63,6 +69,8 @@ sub taxline {
   my $taxable_cents = 0;
   my $tax_cents = 0;
 
+  my $round_per_line_item = $conf->exists('tax-round_per_line_item');
+
   my $cust_main = $self->{cust_main};
   my $custnum   = $cust_main->custnum;
   my $invoice_time = $self->{invoice_time};
@@ -258,7 +266,16 @@ sub taxline {
     $taxable_charged = sprintf( "%.2f", $taxable_charged);
     next if $taxable_charged == 0;
 
-    my $this_tax_cents = int($taxable_charged * $tax_object->tax);
+    my $this_tax_cents = $taxable_charged * $self->tax;
+    if ( $round_per_line_item ) {
+      # Round the tax to the nearest cent for each line item, instead of
+      # across the whole invoice.
+      $this_tax_cents = sprintf('%.0f', $this_tax_cents);
+    } else {
+      # Otherwise truncate it so that rounding error is always positive.
+      $this_tax_cents = int($this_tax_cents);
+    }
+
     my $location = FS::cust_bill_pkg_tax_location->new({
         'taxnum'      => $tax_object->taxnum,
         'taxtype'     => ref($tax_object),
@@ -273,11 +290,18 @@ sub taxline {
     $tax_cents += $this_tax_cents;
   } #foreach $cust_bill_pkg
 
-  # now round and distribute
+  # calculate tax and rounding error for the whole group
   my $extra_cents = sprintf('%.2f', $taxable_cents * $tax_object->tax / 100)
                             * 100 - $tax_cents;
   # make sure we have an integer
   $extra_cents = sprintf('%.0f', $extra_cents);
+
+  # if we're rounding per item, then ignore that and don't distribute any
+  # extra cents.
+  if ( $round_per_line_item ) {
+    $extra_cents = 0;
+  }
+
   if ( $extra_cents < 0 ) {
     die "nonsense extra_cents value $extra_cents";
   }