I just received an email stating that more than one accounts is using my information. How can I check and verify this?

You will receive that email if you are using a different account from last year to file your taxes. I've included a link to contact Customer Support so they can get your situation sorted out.

https://support.turbotax.intuit.com/contact/#/search/I%2520received%2520an%2520email%2520about%2520using%2520different%2520TurboTax%2520accounts

https://ffa.lc.intuit.com/questions/1293786-i-received-an-email-about-using-different-turbotax-accounts