Understanding Data Merge Rules: Add, Append, and Replace Data

Understanding Data Merge Rules: Add, Append, and Replace Data

When importing or transferring contacts in Numero, you can control exactly how each field is updated for contacts that already exist in your list. Rather than applying a one-size-fits-all approach, Numero lets you choose an action for specific fields so that your existing data in those fields intact, gets updated, or gets added to, depending on what you need.

How to Customize Merge Rules

When setting up a contact import or transfer, you'll see a Data Merge section where each supported field has its own action dropdown. Simply select the action you want applied to that field for this import.

Defaults are pre-set based on common use cases, but you can adjust them at any time before running the import or transfer - see screenshot below for reference. 

The Four Merge Rules

Add: Adds new, separate items to a field that holds a collection of values, without affecting what's already there. For example, adding a new Contact Code to a contact that already has Contact Codes -the existing codes are preserved and the new one is included alongside them.

Append: Adds the incoming value to the end of any existing content in the field, preserving what's already there. For example, a field like Notes where you want to keep a running history rather than replace previous text entries.

Replace: Overwrites the existing value with the incoming value entirely. For fields like "Notes" or "Bio," it will remove all existing text in that field and replace it with the data from the import. For fields like "Contact Codes," Replace would remove all existing Contact Codes and apply the new code(s) from the import. 

A Few Things to Keep in Mind

• Import actions only apply to existing contacts. New contacts will always have their fields populated with the incoming data, regardless of the action selected.
• Replace is permanent once an import runs. We don't save historical values. Double-check your selections before confirming.
• When in doubt, Add or Append is the most conservative option and carries the least risk of unintended data loss.