Log into your Simplero account: https://secure.simplero.com/login
Once you've logged in successfully, select the Edit profile button on the top right corner of your profile picture

Once inside your profile page, select Have multiple Simplero IDs? under your profile picture

Enter all the email addresses OR Simplero IDs you may have used, one by one, and click the Send confirmation email button

We'll then send you an email to each address with a link that you need to click. Go to your email and click the link.

Once confirmed, click the blue button "Merge these usernames" to complete the merge.
Your Simplero ID going forward will be the one on the right