taxes/tax_rules.inc

   1 <?php
   2 /**********************************************************************
   3     Copyright (C) FrontAccounting, LLC.
   4         Released under the terms of the GNU General Public License, GPL,
   5         as published by the Free Software Foundation, either version 3
   6         of the License, or (at your option) any later version.
   7     This program is distributed in the hope that it will be useful,
   8     but WITHOUT ANY WARRANTY; without even the implied warranty of
   9     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  10     See the License here <http://www.gnu.org/licenses/gpl-3.0.html>.
  11 ***********************************************************************/
  12 /*
  13         FA tax basic rules.
  14 */
  15 define('TAX_NONE', 0); // none option
  16 define('TQ_NONE', 0); // none option
  17
  18 // implemented taxation options
  19 // basic:
  20 define('TAX_PAYABLE', 1);
  21 define('TAX_DEDUCTIBLE', 2);
  22 define('TAX_CHARGED', 4);
  23 // category depenedent:
  24 define('TAX_DUEDATE', 8);
  25 define('TAX_PARTIAL', 16);
  26
  27 // quirks dependent on vat_categories
  28 define('TQ_NONDEDUCT', 1);      // never deductible
  29 define('TQ_PARTIAL', 2);        // partially deductible (using global factor)
  30 define('TQ_DUEDATE', 4);        // taxable on due date instead of transaction date
  31 define('TQ_REVERSE', 8);        // tax is reverse charged
  32 define('TQ_IMPDEDUCTIBLE', 16); // import tax is deductible
  33
  34 class tax_system
  35 {
  36         //-------------------------- entity taxation rules ----------------------------
  37         // general rules: who and when pays taxes
  38         //
  39         // FIXME: credit notes
  40         //
  41         var     $description;
  42         var $ts_basic_rules;
  43         var $ts_category_quirks;
  44
  45         function __construct()
  46         {
  47                 $this->ts_basic_rules = array(
  48                         TA_DOMESTIC => array(
  49                                 ST_SALESQUOTE => TAX_CHARGED,
  50                                 ST_SALESORDER => TAX_CHARGED,
  51                                 ST_CUSTDELIVERY => TAX_CHARGED,
  52                                 ST_SALESINVOICE => TAX_PAYABLE | TAX_CHARGED,
  53                                 ST_CUSTCREDIT => TAX_PAYABLE | TAX_CHARGED,
  54                                 ST_PURCHORDER => TAX_CHARGED,
  55                                 ST_SUPPRECEIVE => TAX_CHARGED,
  56                                 ST_SUPPINVOICE => TAX_DEDUCTIBLE | TAX_CHARGED,
  57                                 ST_SUPPCREDIT => TAX_DEDUCTIBLE | TAX_CHARGED,
  58                         ),
  59                         TA_EXPORT => array(
  60                                 ST_SALESQUOTE => TAX_NONE,
  61                                 ST_SALESORDER => TAX_NONE,
  62                                 ST_CUSTDELIVERY => TAX_NONE,
  63                                 ST_SALESINVOICE => TAX_NONE,
  64                                 ST_CUSTCREDIT => TAX_NONE,
  65                                 ST_PURCHORDER => TAX_NONE,
  66                                 ST_SUPPRECEIVE => TAX_NONE,
  67                                 ST_SUPPINVOICE => TAX_NONE,
  68                                 ST_SUPPCREDIT => TAX_NONE,
  69                         ),
  70                         TA_EU => array(
  71                                 ST_SALESQUOTE => TAX_NONE,
  72                                 ST_SALESORDER => TAX_NONE,
  73                                 ST_CUSTDELIVERY => TAX_NONE,
  74                                 ST_SALESINVOICE => TAX_NONE,
  75                                 ST_CUSTCREDIT => TAX_NONE,
  76                                 ST_PURCHORDER => TAX_NONE,
  77                                 ST_SUPPRECEIVE => TAX_NONE,
  78                                 ST_SUPPINVOICE => TAX_DEDUCTIBLE | TAX_PAYABLE,
  79                                 ST_SUPPCREDIT => TAX_DEDUCTIBLE | TAX_PAYABLE,
  80                         ),
  81                 );
  82
  83                 //-------------------------- special goods dependent rules  ----------------------------
  84                 //
  85                 $this->ts_category_quirks = array(
  86                         VC_OTHER => TQ_NONE,
  87                         VC_MEDIA => TQ_DUEDATE,                 // is no longer used ?
  88                         VC_ASSETS => TQ_NONE,                   // just separate category in tax reg
  89                         VC_NONDEDUCT => TQ_NONDEDUCT,
  90                         VC_SERVICES => TQ_IMPDEDUCTIBLE,
  91                         VC_PARTIAL => TQ_PARTIAL,
  92                         VC_REVERSE => TQ_REVERSE,
  93                 );
  94         }
  95         /*
  96                 Returns tax options applicable for the arguments set
  97
  98                 $allow_reverse - decides whether reverse charging option is honoured for sales invoice
  99                 (this depends on 'continue transaction' value as defined by law, so have to be set by case).
 100         */
 101         function options($trans_type, $tax_area, $vat_category, $allow_reverse=true)
 102         {
 103                 if (!isset($vat_category)) // exempt goods has really no category
 104                         return TAX_NONE;
 105
 106                 $options = $this->ts_basic_rules[$tax_area][$trans_type];
 107
 108                 // per vat category quirks
 109                 $quirks = $this->ts_category_quirks[$vat_category];
 110
 111                 if ($quirks & TQ_DUEDATE)
 112                         $options |= TAX_DUEDATE;
 113
 114                 if ($quirks & TQ_NONDEDUCT)
 115                         $options &= ~TAX_DEDUCTIBLE;
 116
 117                 if ($quirks & TQ_PARTIAL)
 118                         if ($options & TAX_DEDUCTIBLE)
 119                                 $options |= TAX_PARTIAL;
 120
 121                 if ($quirks & TQ_IMPDEDUCTIBLE)
 122                         if ($tax_area == TA_EXPORT && in_array($trans_type, array(ST_SUPPINVOICE, ST_SUPPCREDIT)))
 123                         {
 124                                 $options |= TAX_DEDUCTIBLE | TAX_PAYABLE;
 125                         }
 126
 127                 if (($quirks & TQ_REVERSE) && (!in_array($trans_type,array(ST_SALESINVOICE, ST_CUSTCREDIT)) || $allow_reverse))
 128                         if ($tax_area == TA_DOMESTIC)
 129                         {
 130                                 $options ^= TAX_PAYABLE;
 131                                 $options &= ~TAX_CHARGED;
 132                         }
 133
 134                 return $options;
 135         }
 136 };
 137
 138 function dbg_tax($options)
 139 {
 140         $dbg_rules = array(
 141                 TAX_PAYABLE => 'payable',
 142                 TAX_DEDUCTIBLE => 'deductible',
 143                 TAX_CHARGED => 'charged',
 144                 TAX_DUEDATE => 'due_date',
 145                 TAX_PARTIAL => 'partial'
 146         );
 147
 148         $opts = array();
 149         foreach($dbg_rules as $key => $name)
 150                 if ($options & $key)
 151                         $opts[] = $name;
 152
 153         _vd(implode($opts, ','));
 154 }