How to Add Subscribers to an Existing List

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Learn how to add subscribers to an existing list by either uploading new contacts from a CSV or by using Quick Add, as detailed in the sections below.

Before adding contacts using either of these methods, turn flows triggered by the list to manual. Once the import is complete, wait a few hours and then set the flow back to live.

Add Subscribers via Upload

  1. Navigate to the list that you want to add subscribers to
  2. Click the Manage List dropdown in the upper right-hand corner 
  3. Select Import Contacts

You will see two options here: Upload file and Upload via copy/paste. Both of these options will allow you to add contacts just as you would if you were creating a new list. 

Upload File

Note that, when you upload a CSV to a list that triggers a flow, the flow will be sent to everyone once they are uploaded. If you do not want this to occur, set your flow to manual. After the import is complete, wait a few hours before going back into the flow and deleting the people who you do not want to receive the email. Then, switch the flow back to live.

  1. Select Upload file
  2. Drag and drop your CSV file or select it from your computer
    In Klaviyo’s Lists & Segments tab, a user opens a list, clicks Import Contacts from the Manage list menu, and begins the import process
  3. Review your import
  4. Map the columns in your uploaded CSV to Klaviyo fields; the Klaviyo fields represent where your data is stored on your contact's profile.
    The Klaviyo Import Review Screen showing the mapping stage of a list import, including two custom properties
  5. If you don't have GDPR consent fields already stored in your CSV:
    1. Click Add GDPR specific consent
    2. Specify the types of consent the contacts on your list have given; this information will then be stored on their profile as custom properties 
  6. If you're uploading Klaviyo-specific fields, the data type is already selected for you and you're unable to modify it
  7. If you're uploading custom properties:
    1. Select the field you'd like to map the properties to 
    2. Select the data type
    3. Add a new custom property by typing the new property name and selecting Create option
      For a custom property in a list upload, the user has typed in a new property name and their cursor hovers over the Create option button
  8. Click Start Import after you finish mapping your Klaviyo fields

Upload via Copy/Paste

  1. Select Upload via copy/paste.
  2. Paste contact information in this format:
    • Email Address First Name Last Name
    • George Washington
    • Abraham Lincoln
  3. Click Start Import when you finish pasting in contacts 

The Upload via copy/paste field of the list import process with a blank field to the left and consent and formatting guidelines to the right

Add Subscribers via Quick Add

If you would like to quickly add a handful of individuals to your list, you can use the Quick Add option instead.

  1. Navigate to the list you'd like to add the profile to
  2. Click Quick Add 

The Quick Add button is highlighted in a lists’ settings in Klaviyo

Note that this option is available only for lists, not segments. 

Best Practices

A few things to keep in mind:

  • Never add contacts to a subscriber list that have not intentionally opted in — this is against Klaviyo’s Terms of Service.
  • We will automatically keep customers from joining the same list more than once. This means that, if you are trying to import a file containing subscribers that are already on your list, you will notice that these duplicative records will not get added. For example, if you want to add a custom property to everyone in a list, you can safely re-upload the list with the custom property attached without creating duplicate profiles.
  • We will automatically skip email address entries that do not have a valid format. A valid email address such as is made up of a local part, an @ symbol, then a case-insensitive domain part. If any of the required parts of a valid email address are missing, we will consider the email invalid. If there are erroneous spaces in the email address, we will also consider the email invalid.

Additional Resources

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