I have an important custom field, Agency, used by all records and I need to change it from a lookup window to a text field so I can use a workflow rule that updates the agency for a contact or opportunity based on agency list in the account. When I click edit and change field type the options are non and lookup window. How can I change this field type or replace it with another field without compromising the data this field has for every record?

1 Answer 1


As per documentation of salesforce there are limitation of changing field type in Salesforce.

Relationships You can convert relationship fields to nonrelationship fields and vice versa, but only on external objects. If your organization has a large number of records, Salesforce displays a waiting page after you have requested to change a master-detail into a lookup relationship or a lookup into a master-detail relationship. After you have created a roll-up summary field on an object, you cannot convert the object's master-detail relationship into a lookup relationship. A lookup cannot be converted to a master detail relationship if there are any existing records on the object that have a null value set for the lookup relationship. If you are converting a master-detail relationship to a lookup for a custom object on the “detail” side, the organization-wide default for the object is automatically updated to Public Read/Write. Similarly, converting a lookup to a master-detail-relationship changes the organization-wide default to Controlled by Parent

Lookup relationship can only be converted into relationship data type. The only exception to this is external Object.

You can't change Lookup relationship to text. I would suggest you to take back up of values of the lookup field and create new text field and update the existing data to the text field.

  • How would I take backup of existing values and then update the existing data? Can you walk me through that process?
    – Dataman434
    Commented Oct 10, 2015 at 19:54
  • 2
    Create a new text field. Then, export the data, making sure to capture the lookup record name with or without the id. In excel, copy the lookup name and paste it in the new text field. Finally, update the new field en mass.
    – smckitrick
    Commented Oct 10, 2015 at 20:28
  • what tool do i use for that?
    – Dataman434
    Commented Oct 10, 2015 at 20:34
  • Appex data loader?
    – Dataman434
    Commented Oct 10, 2015 at 20:34
  • Can someone please provide a walkthrough on exporting the data and then updating it? Would it just be a report of all accounts all time that I export with both the old look up field and the new text field? Then I just replace text field with the values of lookup in excel and upload through data loader?
    – Dataman434
    Commented Oct 10, 2015 at 21:03

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