If Unable to Sign-in, how can i re-activate quickbook account ?

Welcome to the Community space, Skhan.

Let me share some insights on what you can do if you can't sign in to QuickBooks Online.

Forgetting the sign-in information is one of the common causes of this issue. There are a few ways to sign in with just one piece of information, such as your email, phone number, or user ID. 

If you can't remember which email you used, try entering your phone number. Intuit will text you a one-time code to access your account. If you're lockout, you'll see this message: Too many invalid attempts, account is locked out for 15 minutes. After 15 minutes, you can try to sign in again with a phone number, email, or user ID.

Here is the article from Canada but also applicable on your end, for more details about signing in to QBO: Get help if you can't sign in to your QuickBooks Online account.

Moreover, if these errors show on your end: 
 

• The WebPage cannot be found
• Error 404: File Not Found
• QuickBooks Online is currently unavailable, please try again later

Feel free to check out this article: Fix common sign-in errors in QuickBooks Online.

I'll add this article to guide you in effectively handling your business using QBO: Help guides for QuickBooks Online. It contains topics about advanced accounting, banking, and payments.

I'm glad to assist you today. Please come back here if you need additional help. Take care, and have a good day.