I’d recommend double-checking your list settings to see if it’s set to double opt-in or single opt-in. By default, I believe Klaviyo uses double opt-in, which means subscribers receive a confirmation email after submitting the form. If they don’t click the link in that email, they haven’t technically opted in yet according to Klaviyo’s setup. While Klaviyo recommends double opt-in, you can switch to single opt-in if you prefer—each option has its pros and cons.

To review these settings, open the list on Klaviyo, click on Settings, and then go to Consent.

Here is a video: 

Ok now the emails are showing in Audience > Profiles in Klaviyo but it is not showing under the list name which is assigned in the zap. Any ideas why?

Could you verify if you've gone into the settings and disabled double opt-in and selected Single Opt-in ? After that, try refreshing the list manually and make sure you're on a static list for the exact list name you put down, not a segment list. The criteria look good—I created a similar setup and was able to add profiles to the relevant Klaviyo list. Let me know how it goes for you!

Just following up, how did this go for you?

Thank you TomZap. That worked. Now i can see the new subscriber in Profiles and the List i created. 
However, i want subscribers to have the double opt in. So how do i go about having that while still getting these emails to show in Profiles and the selected List? 

Thanks for your response! I’ve tried creating a Zap to subscribe users based on various criteria, and it seems that this option has to be disabled from my research. If this is essential for your workflow, I can raise a case with Zapier to 100% confirm as they may have some workarounds in there internal database as imagine this would be a common question.

In the meantime, here’s a workaround: you could create a custom property in Klaviyo, like 'Source: Zapier.' Once set up, you can create a custom segment list in Klaviyo where the source equals 'Zapier,' which will filter the results accordingly. When you add a contact in Zapier, include this custom property Source: Zapier to ensure it appears in your segment list. You can then export this data or convert it into a list after a few days, though you'll need to replace this list if you convert it.

Hmm i hear what your saying. Thanks tomzap. 
As this zap is for a coming soon landing page i’m happy to turn off the double opt in for now.
When i launch my main site which will be in Shopify, not Squarespace then i will have the opt in, but i think it will be easier from shopify. thank you for your help - much appreciate

No worries! Good luck with your launch on Shopify!

Hi @ARox 

For reference, help links for using Klaviyo in Zaps: https://zapier.com/apps/klaviyo/integrations#help