diff --git a/application/config/constants.php b/application/config/constants.php
index 506f6905..c81e4985 100644
--- a/application/config/constants.php
+++ b/application/config/constants.php
@@ -80,5 +80,64 @@ define('TRP',                            			'DEP07');
 define('COATING',                            		'DEP08');
 define('MAINTENANANCE',                            	'DEP09');
 define('FINANCE',                            		'DEP10');
+
+/* PO Type  */
+define('REVENUE',                            		'REVENUE');
+define('SERVICE',                            		'SERVICE');
+define('IMPORT',                            		'IMPORT');
+define('CAPITAL',                            		'CAPITAL');
+
+// Tax Type
+define('PERCENTAGE',                            		'PERCENTAGE');
+define('LUMPSUM',                            		'LUMP SUM');
+define('NILTYPE',                            		'NIL');
+
+// Freight Type
+define('PERUOM',                            		'PER UOM');
+define('PERTRIP',                            		'PER TRIP');
+
+
+/*  Formula for Tax calculation */
+/* Discount*/
+define('DIS_PERCENTAGE',                            		'((Discountval/100) * basicValue)');
+define('DIS_LUMPSUM',                            		    'Discountval');
+// Packaging
+define('PACKAGING_PERCENTAGE_BYDISCOUNTVALUE',             		'((Packagingvalue/100) * (basicValue-AfterDiscount))');
+define('PACKAGING_PERCENTAGE_BYBASICVALUE',                            		'(Packagingvalue/100) * basicValue');
+define('PACKAGING_LUMPSUM_BYDISCOUNTVALUE',             		'Packagingvalue');
+define('PACKAGING_LUMPSUM_BYBASICVALUE',                            		'Packagingvalue');
+//Excise
+define('EXCISE_ONBASICVALUE',                            		'((ExciseDuty/100) * basicValue)');
+define('EXCISE_ONBASIC_DISCOUNT',                            		'((ExciseDuty/100) * (basicValue-AfterDiscount))');
+define('EXCISE_ONBASIC_DISCOUNT_PACKAGING',                      '((ExciseDuty/100) * ((basicValue-AfterDiscount)+ AfterPackaging))');
+define('EXCISE_ONBASIC_PACKAGING',                            		'((ExciseDuty/100) * (basicValue + AfterPackaging))');
+
+//Vat
+define('VAT_ONBASICVALUE',                            		'((vatValue/100) * basicValue)');
+define('VAT_ONEXICSEVALUE',                            		'((vatValue/100) * (basicValue+ExciseDuty))');
+
+//CST
+define('CST_ONBASICVALUE',                            		'((CSTValue/100) * basicValue)');
+define('CST_ONEXICSEVALUE',                            		'((CSTValue/100) * (basicValue+ExciseDuty))');
+//GST
+define('GSTTAX',                            				'((GSTValue/100) * basicValue)');
+//Other Tax
+define('OTHERTAX',                            				'((OtherTaxValue/100) * basicValue)');
+//Freight Tax
+define('FREIGHT_PERCENTAGE',                            			'((FreightValue/100) * basicValue)');
+define('FREIGHT_LUMPSUM',                            				'FreightValue');
+define('FREIGHT_PERUOM',                            				'FreightValue * Quantity');
+define('FREIGHT_PERTRIP',                            				'FreightValue');
+
+/* Purchase Order Status */
+
+define('PO_DRAFT',                            'ST014');
+define('PO_CREATED',                          'ST015');
+define('PO_INPROGRESS',                       'ST016');
+define('PO_DISPATCHED',                       'ST017');
+define('PO_DELIVERED',                        'ST018');
+define('PO_CANCELLED',                        'ST019');
+define('PO_ONHOLD',                           'ST020');
+define('PO_CLOSED',                           'ST021');
 /* End of file constants.php */
 /* Location: ./application/config/constants.php */
\ No newline at end of file