Best answer by Bradley_OVO
I've slightly changed your question just to make it easier for other customers, having the same issue, to find the answer!
This is usually an issue where customers have either moved properties and set back up with OVO with the same email address. When logging in they would usually find that their old account would automatically open up.
Usually, we would advise customers who've got existing accounts with us to use a new, unique email address to avoid this issue, however, instead you can use your new OVO ID as your username instead of your email. This will make sure that you're always logging into the right account.
Unfortunately, we do not have a current system where customers can access both properties via one MyOVO. This maybe something we aim to implement in the future so watch this space!
Hope this helps you!