Let me guide you in subscribing to QuickBooks Self-Employed (QBSE), hroot3302460-gma.
Unlike QuickBooks Online (QBO), you can use one email address or the same credentials for multiple QBO company. In QBSE, we'll have to use different credentials when subscribing to the program. If we'll select the Sign into existing, it will route you to your existing subscription. In this case, we'll have to use your other credential or google play account to able to successfully subscribe. Once you're done entering your credentials, we'll have to click the One More Step button then enter your billing information to complete the process.
To manage your subscriptions, refer to Update your QuickBooks Self-Employed billing and subscription details article. I've added an article that will help you in setting up your second company in your new QBSE account: Getting started with QuickBooks Self-Employed.
I also highly recommend connecting your bank and credit card accounts to QuickBooks Self-Employed to automatically download your recent transactions.
I'm just one reply away if have any additional questions about QBSE. I'm always here to ensure your success. Have a great day.