> For the complete documentation index, see [llms.txt](https://docs.flowretail.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.flowretail.com/docs/integrations/crm/klaviyo.md).
# Klaviyo
Sync Flow Retail customers and their marketing consents with Klaviyo.
Klaviyo sync keeps your Flow Retail customers and Klaviyo profiles in step, including marketing consent for email and SMS.
***
## What is Klaviyo?
Klaviyo is a marketing automation platform and customer data platform. You use it to send email and SMS campaigns to customer profiles it stores.
***
## How does it work?
The integration syncs in three ways.
**Flow Retail → Klaviyo.** When a customer is created or changed in Flow Retail, their Klaviyo profile is created or updated. This runs in the background, so saving a customer never waits for Klaviyo or fails because of it. The profile gets:
* Name, email, mobile and company name
* Address, city, postal code and country
* Customer type, VAT number, loyalty ID, customer groups and default store, as custom properties
When a mapped consent changes, the customer is subscribed to or unsubscribed from the matching Klaviyo channel.
**Klaviyo → Flow Retail, as it happens.** When someone subscribes or unsubscribes in Klaviyo, the change is recorded as a consent on the Flow Retail customer. This part is optional and needs a webhook (see step 5).
**Klaviyo → Flow Retail, every night.** At 04:00, Klaviyo profiles are imported:
* A profile that matches an existing customer updates that customer's consents where they differ.
* A profile with no match becomes a new customer, if it has a first name, a last name, and an email or mobile. Other profiles are skipped.
* Profiles that were never subscribed, or are waiting for double opt-in, don't count as a "no". Flow Retail records only explicit choices.
{% hint style="info" %}
Consent sync only works for the channels you map in step 4. With no consents mapped, only profile data syncs.
{% endhint %}
***
## Before you start
* A Klaviyo account.
* The Klaviyo extension enabled for you. Contact Flow Retail support to have it added.
* A consent in Flow Retail for each Klaviyo channel you want to sync: email marketing, SMS marketing and SMS transactional.
***
## Set up Klaviyo step by step
{% stepper %}
{% step %}
#### Create a private API key in Klaviyo
In Klaviyo, create a private API key with access to profiles and subscriptions.
{% endstep %}
{% step %}
#### Open the extension
Go to **Admin → Settings → Extensions** and select **Klaviyo**.
{% endstep %}
{% step %}
#### Add the API key
Paste the key into **Klaviyo Private API Key**. Make sure Active is switched on.
{% endstep %}
{% step %}
#### Map your consents
Choose a Flow Retail consent for each channel you want to sync:
* **Consent UID for email marketing**
* **Consent UID for SMS marketing**
* **Consent UID for SMS transactional**
Each consent can be used for one channel only. Missing a consent? Create it under **Admin → Settings → Consents → New Consent**.
Leave **Klaviyo Profiles Reverse-Sync Cursor** as it is — the nightly import manages it. Select **Save**.
{% endstep %}
{% step %}
#### Optional: receive consent changes from Klaviyo
To get subscribes and unsubscribes from Klaviyo straight away, rather than overnight, create a webhook in Klaviyo for subscription events. Point it to:
```
https://api.flowretail.com/v2/tenants//callbacks/klaviyo
```
Paste the webhook's signing secret into **Klaviyo Webhook Signing Secret**. It must be at least 16 characters. Without it, Flow Retail ignores the webhook.
Klaviyo webhooks require a Klaviyo plan that includes them. Contact Flow Retail support if you need your tenant ID.
{% endstep %}
{% endstepper %}
***
## Good to know
* **Two customers, one email.** Each Flow Retail customer gets their own Klaviyo profile, even if two customers share an email address.
* **Only the right contact gets a channel.** Customers without an email aren't subscribed to email marketing, and customers without a mobile aren't subscribed to SMS.
* **Imported customers are marked.** Customers created by the nightly import have Klaviyo as their origin.
*Last updated 24.09.2026*
---
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