How to upload a list of WhatsApp contacts

See how to upload a CSV of your WhatsApp subscribers into Klaviyo. Importing WhatsApp consent is an essential part of migrating providers and consolidating your marketing tech stack. Once this consent is in Klaviyo, you can start messaging your WhatsApp audience from around the globe.

Before you begin

To import a list of WhatsApp contacts with consent, you should:

• Set up WhatsApp in Klaviyo.
• Set any welcome flows to manual mode (those triggered by the Subscribed to WhatsApp marketing or Subscribed to WhatsApp transactional metric or the list you’re importing to).
  • Wait at least 2 hours after importing before you turn your flow live again.

Prepare your CSV for importing

Include a phone number as the first or second column

Klaviyo uses either email or phone number as a profile’s unique identifier.

When importing:

• Use email as the first column if you have an email address for each person.
• Otherwise, use phone number as the first column.

You don’t need a separate country column when each phone number includes a "+" and country code, even if you import both SMS and WhatsApp consent. For more guidance, see how to include the subscriber’s country.

Format phone numbers with a "+" and country code

Enter every phone number in international format: a plus sign (+), then the country code, then the number, with no spaces, dashes, or parentheses.

Numbers without the "+" prefix may not import correctly.

Tip: Spreadsheet apps like Excel and Google Sheets often remove the leading "+" automatically, including when you paste a number or open an exported CSV. To keep it:

• Format the phone number column as Text before you enter or paste the numbers.
• Or type an apostrophe before the number (for example, '+85212345678).
• Check the column again before you save and upload the CSV.

Before re-importing phone numbers exported from Klaviyo, check that each number still starts with "+". Add it only if it is missing.

Optional: indicate if consent is for marketing or utility WhatsApp messages

Currently, you can import consent for either marketing or utility (also called “transactional” in Klaviyo) WhatsApp messages.

If your CSV contains a mix of both, you can indicate the type of consent by adding 2 columns and labeling them:

• WhatsApp Marketing Consent
• Marketing consent allows you to send any type of WhatsApp: both promotional (product announcement, abandonment reminder, etc.) and transactional messages.
• WhatsApp Transactional Consent
• WhatsApp transactional consent means you can only send Meta-approved utility messages.

Optional: add consent status (subscribe, unsubscribed, never subscribed)

Including the consent status is recommended if your CSV includes a mix of either:

• Subscribed and unsubscribed subscribers
• Marketing- and transactional-only subscribers

There are 3 consent statuses available:

• Subscribe
  Person is opted in to receive messages.
• Unsubscribed
  Person used to be subscribed but has since opted out. Importing this value records an opt-out for the corresponding WhatsApp message type. Consent for other channels is separate (e.g., an SMS opt-out does not automatically opt someone out of email).
• Never subscribed
  Person never consented to that message type. Importing this value does not add consent or remove any consent already stored in Klaviyo.

A blank consent cell leaves existing consent unchanged unless the corresponding consent timestamp is populated. A timestamp without a consent value is treated as consent to subscribe.

Optional: add consent timestamp

While optional, the timestamp is usually good to include if it’s available. To do so, check that:

• The timestamp is in an accepted date/time format, such as 2026-01-15T14:30:00Z.
• The column is labeled either:
  • WhatsApp Marketing Consent Timestamp
  • WhatsApp Transactional Consent Timestamp (for transactional consent)

If you include a consent status without a timestamp, Subscribe can still add consent. If you omit both WhatsApp consent and timestamp columns, confirm WhatsApp consent during the import.

Include the original consent timestamp when it is available. If a profile’s opt-out is more recent than that timestamp, consent won't be re-added. Only re-subscribe someone who has opted in again after opting out, using their new consent timestamp.

Import a list of phone numbers with WhatsApp consent

1. Navigate to Audience > Lists & segments.
   

2. Select the list you want to add your contacts to (e.g., WhatsApp Subscribers).

3. Open the Manage list dropdown in the upper right.

4. Choose Import contacts from the dropdown.

• You must be an Owner, Admin, or Manager to use this option.
  

5. Click Upload and select your CSV file of WhatsApp subscribers.

6. Map each column from your CSV to the appropriate Klaviyo property, including Phone Number and any WhatsApp consent or timestamp fields. Make sure each phone number starts with "+" and the country code (see "Format phone numbers with a '+' and country code" above).

Mapped WhatsApp consent and timestamp columns determine each profile’s consent. If you map one of these columns, WhatsApp will not appear in the later bulk consent choices.

• Example: if you include a WhatsApp Transactional Consent column (but not one for marketing consent).
  • Subscribe adds WhatsApp transactional consent. It does not add or remove marketing consent.
  • Unsubscribed records a transactional opt-out. Never subscribed leaves existing consent unchanged.

7. If you see Next, click it and complete the consent confirmation below. If you see Import, skip to step 8.

• Under Did these contacts subscribe to messaging?, select Yes only if you have consent to apply to all imported contacts for the channels you select. To leave consent unchanged for the channels not covered by your CSV, select No and skip to step 8.

• If you selected Yes, choose only the channels these contacts consented to. Select Email or Text Message only if you also want to import consent for those channels.
• If WhatsApp is offered, choose the message types to apply:
  • For transactional-only consent, select Transactional messages and leave Marketing messages unselected.
  • For both types of consent, select Marketing messages and Transactional messages.
  • For marketing-only consent, select Marketing messages and leave Transactional messages unselected.

8. When ready to proceed, click Import.

The import process can take up to a couple of hours to complete.

Once all the numbers are imported, Klaviyo will either create a new profile or associate the data to an existing profile. For instance, if you import a phone-number-only CSV, Klaviyo will look for profiles with the same phone number, update that profile's WhatsApp consent according to the CSV values or the consent types you selected, and include any other profile properties attributed to that contact.

Next steps

Collect WhatsApp consent

About WhatsApp deliverability

How to create a WhatsApp template