A: Hey there, Sumo-ling! Thank you for your question.

Yes, it's possible to stack more codes to increase your limits, and the maximum number of codes you can stack per account is 10.

So, for example, If you already bought one code (Single Plan), getting 2 additional codes and redeeming them for your account will upgrade your plan to the Multiple Plan (3 codes), which includes unlimited sites.

You can stack the additional codes in the Pricing & Plans section of your Squirrly SEO Cloud Account. All you have to do is enter your extra AppSumo codes, one by one, in the "AppSumo Code" field. Click on "Apply Code" and you will be able to see your extended account limits in Account Info.

You can purchase additional codes as long as this deal is still live on AppSumo.

Hope this helps but let me know if you have any other questions.