A master record is the record retained after a duplicate group is removed or merged. Datablist calls this the Record to keep.

The retained record matters because its ID survives the operation. This is especially important when cleaned rows must be synchronized with a CRM.

Record to keep compared with merged values

The record to keep and the values to keep are separate choices.

Conflict resolution in data merging explains how to choose between different field values while retaining the selected record.

In Remove mode, the retained record remains unchanged and the other records are deleted. In Merge mode, empty properties can be filled from duplicate records, text values can be combined, and conflict rules can select values from another record while the retained record ID stays the same.

📌 Short version

The duplicate merge rule selects the surviving row and its field behavior. Field rules select the values written into that row during a merge.

Datablist record-to-keep rules

Datablist supports:

  • Most Complete
  • Last updated
  • First created
  • Highest value on a property
  • Lowest value on a property
  • Matching value on a property

Most Complete is the default. The Free plan applies it automatically, while paid plans can configure another rule.

If a Matching value rule finds no qualifying record in a group, Datablist leaves that group in Needs review.

Which date should choose the master record?

Use Highest value on a property with an imported date column when you want the newest record from the source system. For example, two CRM rows may share an email but have Source Updated At values of 2026-08-12 and 2026-09-24. The September row survives when that Date property is selected.

The built-in Last updated rule uses the item's modification date in Datablist. It does not automatically read a CRM's exported timestamp. Likewise, First created uses the item's creation date in Datablist. To retain the oldest source record, use Lowest value on a property with the imported creation date instead.

Import timestamps as a Date property and inspect missing dates before processing. A newer timestamp indicates a later edit, but does not prove that every field is more accurate. Preview the field values alongside the selected record.

For contact lists, lead deduplication explains which identifiers to compare before choosing a surviving record. A master-record rule chooses the row to keep; it does not establish identity.

Keeping a source record ID

Datablist retains the ID of the surviving Datablist item. An imported CRM ID is a separate property. Check its merge rule so that the output still contains the identifier your CRM expects for an update. Keeping the Datablist item does not itself update the corresponding contact in another system.

Use the merge duplicate leads guide for a CRM example, or see the complete Record to keep reference.