Copy related list from Lead to Account/Contact/Opportunity

There is a salesforce limitation that when a Lead is converted to Account, all the related objects records are lost. E.g. for a Lead, there is a related object named products in which a lead is interested. So for a lead, we can add multiple products in the Lead related list. But when we convert lead to Account, all the products related to Lead are gone!!

So for this, I have written a small code which explains how using a small trigger and few fields, we can retain the products by linking them to account, opportunities and contact. 

I have used a general term CustomObject__c(replace it with you real related object name).

Step 1)For each custom object related to Lead we need to introduce 3 fields.

  -Account__c

  -Contact__c

  -Opportunity__c

Step 2) Write a trigger on before update event on Lead viz. LeadBeforeUpdate

trigger LeadBeforeUpdate on Lead (before update) {

//This trigger will associate a Custom Object record with the new contact and account when Lead is converted

//The Custom Object is associated to an opportunity only if an opportunity record exist on the Lead.

   

    Set<Id> leadIds = new Set<Id>();

    Map<Id,Id> LeadIdContactId = new Map<Id,Id>();

    Map<Id,Id> LeadIdAccountId = new Map<Id,Id>();

    Map<Id,Id> LeadIdOpportunityId = new Map<Id,Id>();

    for (Integer i = 0; i < Trigger.new.size(); i++){

        if (Trigger.new[i].IsConverted == true && Trigger.old[i].isConverted == false){

             leadIds.add(Trigger.new[i].id);

             LeadIdContactId.put(Trigger.new[i].id,Trigger.new[i].ConvertedContactId);

             LeadIdAccountId.put(Trigger.new[i].id,Trigger.new[i].ConvertedAccountId);

             LeadIdOpportunityId.put(Trigger.new[i].id,Trigger.new[i].ConvertedOpportunityId);

        }

    }

   

    //Create a list of CustomObject__c to be updated

    List<CustomObject__c> CustomObjectsToUpdate = new List<CustomObject__c>();

       

           

    List<CustomObject__c> customObjectEntries = [select Contact__c, Opportunity__c, Account__c, Lead__c from CustomObject__c where lead__c in :leadIds];       

   

    for (Lead lead : [select id,ConvertedContactId,ConvertedOpportunityId,ConvertedAccountId from Lead where id in: leadIds])  {

             for (CustomObject__c CustomObject : customObjectEntries) {

                if (CustomObject.Lead__c == lead.Id) {

                    CustomObject.contact__c = LeadIdContactId.get(lead.id);

                    CustomObject.opportunity__c = LeadIdOpportunityId.get(lead.id);

                    CustomObject.account__c = LeadIdAccountId.get(lead.id);

                    CustomObjectsToUpdate.add(CustomObject);

                 }

            }

     }

     if(CustomObjectsToUpdate.size()>0)

         update CustomObjectsToUpdate;

      

} //End of trigger

Note: This trigger will work for multiple records to be copied and is bulk efficient.