Hi Avaneesh,

Thank you very much. 

I have followed your insturction and code and my trigger is as below. I have an error message "Error: Compile Error: Invalid bind expression type of Student__c for column of type String at line 9 column 20"   On the Student__c object this field is auto number, but on Person Account it is a text field, any idea, on how to correct this in trigger.

trigger CreatePersonAccountfromStudent on Student__c (after insert,after update)
{
    List<account> acc=new List<account>();
    Map<Id, Id> m = new Map<Id, Id>();
    RecordType rt = [select id from RecordType where SobjectType='Account' and Name='Student' Limit 1];
 
   if(trigger.isUpdate){
 
   for(account acc:[select id, nric__pc, student_Id_from_student_Prospects__pc from account where student_Id_from_student_Prospects__pc IN : trigger.new]){
       m.put(student_Id_from_student_Prospects__pc , acc.id);   
}
}
    for(student__c stud:Trigger.New){   
      account ac = new account();
        if(trigger.isupdate){ // add this line here
      ac.id = m.get(stud.id).id;
      }
        ac.Autocreated__pc=True;
        ac.Block__pc=Stud.Block__c;
        ac.Bulk_Load__pc=Stud.Bulk_Load__c;
        ac.Current_Acedamic_Year__pc=Stud.Current_Acedamic_Year__c;
        ac.Date_of_Collection__pc=Stud.Date_of_Collection__c;
        ac.Discount_Percentage__pc=Stud.Discount_Percentage__c;
        ac.Discount_Policy__pc=Stud.Discount_Policy__c;
        ac.Discount_Remarks__pc=Stud.Discount_Remarks__c;
        ac.Discount_Type__pc=Stud.Discount_Type__c;
        ac.English__pc=Stud.English__c;
        ac.Event_Name__pc=Stud.Event_Name__c;
        ac.Exclude_Registration__pc=Stud.Exclude_Registration__c;
        ac.Father_Email__pc=Stud.Father_Email__c;
        ac.Father_Name__pc=Stud.Father_Name__c;
        ac.Father_NRIC__pc=Stud.Father_NRIC__c;
        ac.Father_Office_Phone__pc=Stud.Father_Office_Phone__c;
        ac.Father_Primary_Contact__pc=Stud.Father_Primary_Contact__c;
        ac.Father_Remark__pc=Stud.Father_Remark__c;
        ac.Father_Staff__pc=Stud.Father_Staff__c;
        ac.Gender__pc=Stud.Gender__c;
        ac.GEP__pc=Stud.GEP__c;
        ac.Guardian_Email__pc=Stud.Guardian_Email__c;
        ac.Guardian_Mobile__pc=Stud.Guardian_Mobile__c;
        ac.Guardian_Name__pc=Stud.Guardian_Name__c;
        ac.Guardian_NRIC__pc=Stud.Guardian_NRIC__c;
        ac.Guardian_Office_Phone__pc=Stud.Guardian_Office_Phone__c;
        ac.Guardian_Primary_Contact__pc=Stud.Guardian_Primary_Contact__c;
        ac.Guardian_Relationship__pc=Stud.Guardian_Relationship__c;
        ac.Guardian_Remarks__pc=Stud.Guardian_Remark__c;
        ac.Guardian_Staff__pc=Stud.Guardian_Staff__c;
        ac.How_did_you_hear_about_us__pc=Stud.How_did_you_hear_about_us__c;
        ac.Is_Mind_Stretcher_Staff_Mother__pc=Stud.Is_Mind_Stretcher_Staff_Mother__c;
        ac.LastName=Stud.name__c;
        ac.Level__pc=Stud.Level__c;
        ac.Level_Promoted_DateTime__pc=Stud.Level_Promoted_DateTime__c;
        ac.Maths__pc=Stud.Maths__c;
        ac.Mobile_No_Father__pc=Stud.Mobile_No_Father__c;
        ac.Mother_Email__pc=Stud.Mother_Email__c;
        ac.Mother_Name__pc=Stud.Mother_Name__c;
        ac.Mother_No_Mobile__pc=Stud.Mobile_No_Mother__c;
        ac.Mother_NRIC__pc=Stud.Mother_NRIC__c;
        ac.Mother_Office_Phone__pc=Stud.Mother_Office_Phone__c;
        ac.Mother_Primary_Contact__pc=Stud.Mother_Primary_Contact__c;
        ac.Mother_Remark__pc=Stud.Mother_Remark__c;
        ac.Mother_Staff__pc=Stud.Mother_Staff__c;
        ac.MS_Start_Kit_Bag__pc=Stud.MS_Start_Kit_Bag__c;
        ac.Nationality__pc=Stud.Nationality__c;
        ac.NRIC__pc=Stud.NRIC__c;
        ac.NTUC_10_Discount__pc=Stud.NTUC_10_Discount__c;
        ac.NTUC_Card_Expiry__pc=Stud.NTUC_Card_Expiry__c;
        ac.NTUC_Remark__pc=Stud.NTUC_Remark__c;
        ac.Others__pc=Stud.Others__c;
        ac.Others_How_did_you_hear_about_us__pc=Stud.Others_How_did_you_hear_about_us__c;
        ac.Person_Contact__pc=Stud.Person_Contact__c;
        ac.PersonBirthdate=Stud.DOB__c;
        ac.PersonHomePhone=Stud.Home_No__c;
        ac.PersonMailingPostalCode=Stud.Postal_Code__c;
        ac.PersonMailingStreet=Stud.Street_Temp__C;
        ac.Primary_Contact_Number__pc=Stud.Contact_number__c;
        ac.Primary_Email__pc=Stud.Primary_Email__c;
        ac.Primary_Name__pc=Stud.Primary_Name__c;
        ac.Primary_Remark__pc=Stud.Primary_Remark__c;
        ac.Promotion__pc=Stud.Promotion__c;
        ac.Reading_Oceans_Email__pc=Stud.Reading_Oceans_Email__c;
        ac.Reading_Oceans_End_Date__pc=Stud.Reading_Oceans_End_Date__c;
        ac.Reading_Oceans_Start_Date__pc=Stud.Reading_Oceans_Start_Date__c;
        ac.Reading_Oceans_Subscrip__pc=Stud.Reading_Oceans_Subscrip__c;
        ac.recordtypeid=rt.id;
        ac.Registration_Centre__pc=Stud.Registration_Centre__c;
        ac.Related_Centres__pc=Stud.Related_Centres__c;
        ac.Remarks__pc=Stud.Remarks__c;
        ac.RO_Date_Send_User__pc=Stud.RO_Date_Send_User__c;
        ac.RO_Remark__pc=Stud.RO_Remark__c;
        ac.RO_Type__pc=Stud.RO_Type__c;
        ac.Safra_Card_Expiry__pc=Stud.Safra_Card_Expiry__c;
        ac.Safra_Card_Holding__pc=Stud.Safra_Card_Holding__c;
        ac.Safra_Remark__pc=Stud.Safra_Remark__c;
        ac.Salesforce_Id_from_Student_Object__pc=Stud.ID;
        ac.School__pc=Stud.School__c;
        ac.Science__pc=Stud.Science__c;
        ac.Secondary_Stream__pc=Stud.Secondary_Stream__c;
        ac.Start_Date__pc=Stud.Start_Date__c;
        ac.Street__pc=Stud.Street__c;
        ac.Student_Id_from_Student_Prospects__pc=Stud.name;
        ac.Student_Old_Reference_ID__pc=Stud.Student_Old_Reference_ID__c;
        ac.Student_Status__pc=Stud.Student_Status__c;
        ac.Student_Type__pc='Student';
        ac.Tick_to_activate_inter_branch_discount__pc=Stud.Tick_to_activate_inter_branch_discount__c;
        ac.Type_Course_Fee__pc=Stud.Type_Course_Fee__c;
        ac.Unit_Number__pc=Stud.Unit_Number__c;
        acc.add(ac);
     }
   if(acc.size>0){
   upsert acc;
}
}