Merge – Purge Duplicate Identification

Advanced contact data matching algorithms identify duplicates across databases.

Cleanlist’s Merge-Purge Duplicate Identification service uses advanced “fuzzy” name and address matching algorithms to identify duplicates across two or more databases, even when the content, formatting and syntax of the data is different.

Each database can be assigned a priority level to use in determining which record in a duplicate set survives. For example, if a Merge-Purge is performed between a customer and prospect file; typically the customer record survives and the prospect record is flagged for deletion. Priority rules may be as simple or complex as necessary. It’s also possible to consolidate the data from two or more records and create one best-of-all record, although this is not included with Cleanlist’s base Merge-Purge service (contact Cleanlist to discuss your unique requirements).

When performing a Merge-Purge service, Cleanlist first ensures that each source file is duplicate-free by applying its Duplicate Elimination service. (This is also referred to an “intra-file” duplicate elimination vs. the Merge-Purge which is an “inter-file” de-duplication process.)

You choose whether the objective is to identify multiple instances of the same individual (called “Individual Level” match), or different individuals at the same household address (called “Household Level” match).

When you order this service, you receive a consolidated result file containing all records from each source file, in a standardized format and with duplicates flagged for easy identification and/or removal.

An included summary report provides statistical data describing your results.


  1. Useful when combining databases from different departments or businesses.
  2. Avoids errors that typically occur with traditional “string match” techniques.
  3. Increased accuracy of customer / prospect / member data analysis.
  4. Reduce environmental and financial costs associated with duplicated records.
  5. Avoid aggravating customers with unwanted repeat mailings.

Service Channels


Match Rates

2% - 20% Range.

Match Rate Factors:

  • List quality (accuracy, completeness and format)
  • List type (profile, function, demographics)

Related Products

Fields Appended

Field Name

Duplicate Flag:

  • X = Duplicate
  • - = No Match/Non-Duplicate
Duplicate ID:
This column contains the duplicate set ID. All records in a duplicate set have the same ID number.

For advice, estimates, or to place an order,

call us at 1-800-454-0223 or email