Hello, CathJude,
The system will detect that there's a QuickBooks Self-Employed account associated with your login credentials. Cancelling the QBSE subscription won't cut it. What needs to be done is to change the username and email address on your QBSE account or use a different email to sign up for QuickBooks Online Essentials.
If you opt to change the credentials, I recommend contacting QBSE support to help you further: https://help.quickbooks.intuit.com/en_GB/contact?product=qbse. We will be able to pull up your account and assist you.
The subscription fee is £8 for QBSE without the 50% off for first six months. If you have availed the Buy now offer, it should be £4 for QBSE and £9 for QuickBooks Essentials.
Don't hesitate to post in the Community if you have any concerns.
