Salesforce: Lead Conversion Field Mapping

When you convert a Lead, standard Lead fields automatically converted into Account, Contact, and Opportunity - as mapping below:

Lead Field	Maps to
Address	Account: Billing Address Contact: Mailing Address
Annual Revenue	Account: Annual Revenue
Campaign	Opportunity: Primary Campaign Source If the lead has multiple associated campaigns, the most recently associated campaign is inserted into the opportunity regardless of whether the user has sharing access to it.
Company	Account: Account Name Contact: Account Opportunity: Account Name Opportunity: Opportunity Name
Company Name (Local)	Account: Account Name (Local)
Description	Contact: Description
Do Not Call	Contact: Do Not Call This field is not updated for leads converted to existing contacts.
Email	Contact: Email
Email Opt Out	Contact: Email Opt Out This field is not updated for leads converted to existing contacts.
Fax	Account: Fax Contact: Fax
Fax Opt Out	Contact: Fax Opt Out
First Name	Contact: First Name
First Name (Local)	Contact: First Name (Local)
Industry	Account: Industry
Last Name	Contact: Last Name
Last Name (Local)	Contact: Last Name (Local)
Lead Owner	Account: Owner Contact: Owner Opportunity: Owner
Lead Source	Account: Lead Source Contact: Lead Source Opportunity: Lead Source Person Account: Lead Source
Mobile	Contact: Mobile
No. of Employees	Account: Employees
Partner Account	Opportunity: Partner Account This field is not updated for leads converted to existing opportunities.
Phone	Account: Phone Contact: Phone
Rating	Account: Rating
Title	Contact: Title
Website	Account: Website

As you see from above mapping, Lead Source is only mapped to Contact and Opportunity, not to Account Source, but if you need it, here is the workaround by using custom Account Source field - Map Lead Source field on Lead object to Account Source field on Account object during lead conversion. If you aware the default Account Source picklist values are sync with Lead Source, so you may need to make sure this custom Account Source picklist values need to manually sync. At some points, Lead Source to Account Source mapping has been automated by Salesforce.

If you are not using custom fiscal years, the Close Date of the opportunity created is automatically set to the last day of the current fiscal quarter.

If you are using custom fiscal years, the Close Date is the last day of the current fiscal period. If you are using custom fiscal years and a fiscal year has not been defined for the current date, the Close Date is the end of the current calendar quarter.

Custom lead fields only can be converted into custom account, contact, and opportunity fields as specified by the system administrator (not map to the standard field). To specify the mapping for custom lead fields:

1. From Setup, click Customize | Leads | Fields | Map Lead Fields.
2. For each custom lead field, choose a custom account, contact, or opportunity field into which you want the information inserted when you convert a lead.
3. Click Save.

It's best practice to map custom lead fields to other custom fields with the same field type, but here some exceptions and tightened:

• You can only map Number to Number, Currency to Currency, and Percent to Percent field with the exact same field length and same decimal point.
• The lookup field only can be mapped to other lookup fields with the same lookup object.
• You can map from Text and Text Area to Picklist, even the text value does not exist in picklist value.
• You can map from Picklist to Text, Text Area, and Long Text Area, but if the picklist value is longer than the length of the text field, it will throw system error upon conversion process - System.DmlException: Insert failed. First exception on row 0; first error: STRING_TOO_LONG
• You can map from Auto Number, Text and Text Area to Text, Text Area, and Long Text Area field.
• You can map from a Formula field in lead, it treats as a normal field depends on the formula return type.
• You cannot map a Formula field into account, contact, and opportunity.
• Standard lead picklist fields that are blank are mapped to the default picklist values for the account, contact, and opportunity (remember to check default value if you are using Record Type for the target object).

Reference:

• Lead Source fields
• Lead Conversion Field Mapping
• Map Custom Lead Fields