Hello @usermatthewhillcarpe,
Ideally, login credentials for QuickBooks access through signing in and subscription are the same.
But if you purchase your subscription via the app on a mobile device, the email and password used may be different since the billing is handled directly by the app provider.
In the same manner, here's an article you can read to learn more about how you can reactivate your account: Resubscribe to QuickBooks Self-Employed.
On top of that, I've also included this reference for a compilation of articles you can use while working with us: QuickBooks Self-Employed Overview.
If you have any other questions, please let me know by leaving any comments below. I'll be here to lend a hand.
