Why do I have duplicate Person records in my Nation?

Official response from

When you import people to your nation from another source, NationBuilder matches up the imported people with those already in your nation's database. The import process will check to see if each record already exists in your nation by comparing the content of the new records with the content of your existing people records.

If the unique ID for the person you are importing matches someone already in your nation, then the person is updated. If it doesn't match and there is enough  information to create a new person, that person will be created. (Sometimes, it seems there is enough information to create a new person, but what is created is a duplicate of someone in the nation already.) If it there isn't something that can be used as a unique identifier for the person, the record is not imported and is instead added to your error file.

What can I do about duplicate records that are already in my nation?

Once a day, NationBuilder will automatically group all the profiles that appear to be duplicates and allow you to click through on the potential matches to easily accept or reject a merger. You can merge a person for whom you've imported two different email addresses from two different sources and who also follows you on Twitter, for example. You can start reviewing potential dupes by going to People > More > Dedupe.

What can I do to prevent the duplicates from being imported in the first place?

These are the key fields that determine whether a person from a new import will be merged into an existing record:

  • The ID numbers for each record you are importing are compared to the ID numbers for your existing people records (see How can I avoid duplicates when I import people)
  • The name and phone number of each record being imported is compared to the name and phone number of the each of the existing records.
  • The name and email address of each record being imported is compared to the name and email address of each of the existing records.
  • Information provided by social media sites may or may not exactly match your existing information.

When information in the new records exactly matches existing records, the imported records are merged into the existing records. In this case, no duplicates will occur. 

If the ID number matches one in the system, (and it doesn't matter if the ID number is the NationBuilder ID, the voter ID, the external ID, or any other of the ID fields), your imported information will update the record with that ID. When the ID number doesn’t match an existing ID number, a new record will be created.

When the phone numbers or email addresses in the import file don’t exactly match what is already in your nation, you will end up with duplicate records in your data. 

If there are multiple phone numbers attached to a name, unique records will be created for each set of numbers. Let’s say Sam Jones has two phone numbers. Importing Sam from different sources could give you as many as four records:

  • One record with both phone numbers
  • One record with each phone number
  • One record with no phone numbers

If a person provides multiple primary email addresses, you will end up with one record for each email address. If the email address in the import record exactly matches one already in the system for this person, no duplicate should be created. If even one character is different, NationBuilder will create a new record for the new name and email pair. 

If people have signed up for your Nation from Facebook or Twitter, NationBuilder will only match them to existing records if the information they provided to Twitter/Facebook is exactly the same as the information already in your nation.

Where can I find more information on data imports and duplicate records?

Check out these additional FAQ responses:

How do I merge duplicate records?

How can I avoid duplicates when I import?

Finding and merging duplicate profiles in your nation


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