Custom field type conversion data loss
Key Takeaway
The safest approach is to convert only custom fields that have no data yet, because changing the type of a field that already holds data can cause data loss.
You can change the data type of an existing custom field, for example from Text to Text Area (Long). Some conversions keep your data, but many can delete or cut off values, and some are blocked entirely. An app builder needs to know which is which, so they can pick the right type up front or plan a safe change.
Conversions that can cause data loss
These conversions can cause data loss:
- To or from Date or Date/Time
- To Number, Percent, or Currency from any other type
- From Checkbox to any other type
- To or from Multi-Select Picklist, which you may also see as Picklist (Multi-Select)
- From Text to Picklist
Data loss has side effects beyond the field. If data is lost, any list view based on the field is deleted. Assignment and escalation rules can also be affected.