To create an update file generate a report of the Accounts and/or Contacts that you would like to update, export the data to a CSV file, update the data in Excel, and then re-import the information to update all of the file's records at one time.
1. From the Reports Tab, run a report of the records you wish to update, including the columns that should be updated.
2. Export the report to Excel being sure to include your unique identifiers. (For Account updates, these are the Account Id, Account Name, and Account Site exactly as they appear in the application. For Contact updates, your unique identifiers are the Contact Id, Email, or Contact Name (First & Last) as well as the Account Name and Account Site). See Export a Report for more details.
3. Open the export in Excel and change the records (rows) field's (column's) values with the data that should be updated**.
4. Save the changes in Excel as a Comma Separate Value (.CSV) file.
5. In Salesforce navigate to Setup | Administration Setup | Data Management | Data Import Wizard.
6. Select "Launch Wizard!"
7. Select the desired object for What kind of data are you importing? and choose the appropriate selection for What do you want to do?
8. IF YOU ARE UPDATING EXISTING ACCOUNTS, be sure to select the "Update existing Account information" check box. Note: Existing contact record data is automatically overwritten with the data in the import file.
**Do Not alter Record Owner, Account Name, Account Site or Contact Name, as this will result in the creation of duplicate accounts or contacts. You can also match by Account and Contact Id.
The import wizards will not replace or clear out existing data contained in fields with blank values in the import file. To clear data contained in a specific field for multiple records users can leverage list views. See Creating Custom List Views and Editing Records Directly From Enhanced Lists for detailed information. Alternatively, if your organization is API enabled you can leverage the Data Loader to clear existing field values as outlined in How can you update records with Blank values using Data Loader?
If the field you wish to update is a standard picklist field, you can use the replace picklist functionality to perform a mass update instead of utilizing the import wizards.
If you have accounts or contacts with the same name, the import may update the incorrect record. Please ensure that your account and contact names are unique before using this process.
There are several fields in Salesforce that cannot be updated via an Account/Contact Import. Some of these fields are used to deduplicate Accounts and Contacts. These fields include:
Parent Account Name
Contact First Name
Contact Last Name
How do I update records using the Data Import Wizard?
How do I add existing record's Salesforce Ids in my import file?
Perform Mass Updates