Hi there @Woodhope, 

Sorry to hear you’re having some trouble, happy to help! 

Great troubleshooting steps so far! 

I'd also advise ensuring that your API key created in Mailchimp has properly been entered in your integrations page within Klaviyo. Additionally, if you're still running into issues, I'd advise completely removing the integration from Klaviyo again and starting again from scratch, per this documentation, including creating a new API key to try to start fresh!

Let me know if this works for you! 

-Taylor 

Hi @Woodhope, just adding here to @Taylor Tarpley excellent answer, it may take a while for all the data from Mailchimp to show up in Klaviyo.  Mailchimp has some rate limiting, so depending on how much data you have in Mailchimp, it can sometimes take a few hours or even a couple of days for all the historical data to show up.

Thanks a lot to you both. Unfortunately none of these solutions solved my case.

1. The API is working correctly
2. Removing the integrations and starting again doesn’t work either
3. The list i’m importing is very small (about 1500 subscribers), and even after 2 days the data don’t show up.

To detail further, all the data related to shopify (purchases) are showing up, while all the data related to Mailchimp are basically non-existent. I obviously double checked and in mailchimp all the opens and clicks are correctly displayed on the properties of the user. They’re just not transfering to Klaviyo, where every profile appears with no past data.

Hi all, 

After conversing with our Support team, our Community member found the reason their data not importing from Mailchimp was the fact that their data was over 90 days old. As stated in our migration from Mailchimp documentation, Klaviyo only migrates data from the past 90 days. 

If there is any data to import that is not included in this time frame, you can export this data from Mailchimp and import it into Klaviyo via a CSV file. 

Hope this helps anyone else facing this issue in the future! 

-Taylor