Following Tax classes used to calculate tax for sales order in axapta     1. Taxsales   2. Tax   3. TaxRegulation.     In Tax class there is  a method CalcTax on which tax calculate for particular tax code. First tax itemgroup takes from Sales Line then its take formula then formula evaluated by using evabuf method.     tmptaxworkTrans is a temporary table which shows temporary tax calculation.If there is tax adjustment then you need to apply tax button on salestax form to get effects.      Corrected Tax or tax adjustment stored in field SourceRegulateAmountCur of Tmptaxworktrans and    Regular tax  field is  sourceTaxAmountCur.     Before posting table is    tmptax and tmptaxworktrans,tmptaxregulation     After posting Tax table is    TaxTrans,ledgerTrans,CustInvoiceJour.        
Microsoft Dynamics Ax,AIF,Axapta, Enterprise portal,,Microsoft , United State,U.S., SharePoint , BI Tools, Performance Tuning, SSRS,Business Logic,Ax ERP Errors and solution,Dynamics 365 Errors Solution,Business software .