Hello @E T H I C A L E,

Welcome to Klaviyo! 

Klaviyo’s billing plan is based on both the number of Active Profiles you have within your Klaviyo account as well as the number of messages sent to that number of contacts. 

There are two primary ways contacts are added to your Klaviyo account:

• By opting-in via one or more sign up forms/subscribe pages located on your website
• General engagement via one or more integrations you have connected to your Klaviyo account such as making a purchase, abandoning a cart, etc.

With an ecommerce store, Klaviyo syncs customer activity in real-time. If a customer engages with your site, we will create a new profile if one doesn't exist already. These individuals will have contact profiles in your account, but they may not be on any list and would still be considered Active unless suppressed. What is defined as an Active profile is further elaborated in the Understanding Who Is in Your Account article Klaviyo offers. 

Despite having 1150 active profiles, you can certainly be on a lower tiered plan of your choice. Keep in mind though that this would limit you to the number of emails you can send. For example, despite having 1150 profiles, you can still select and use Klaviyo’s $20 a month plan which supports 500 contacts. However, this would limit you in the number of recipients you can have within a campaign to 500 recipients; as defined by your Klaviyo plan. 

I’ve also provided other Community posts along the same subject that may be helpful in understanding how Klaviyo bills below:

I hope this helps! Have a great day!

David

Thanks so much for your very comprehensive reply, that helps a lot