If your QBO account is more than 90 days, it is better you cancel it and open a NEW QBO account.
Otherwise, you can try to purge it:
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If your QuickBooks are less than 90 days old you can wipe the data and begin as new by following the steps below:
1) Sign in to QuickBooks Online.
2) Look at the URL in your browser's address bar. Delete everything after the last / and enter purgecompany.
A pop-up window will appear with a data summary of the account. Type 'YES' to confirm if you wish to delete.
If your account is older than 90 days, you would need to delete data manually or cancel the account and sign-up for a new company from our website > https://quickbooks.intuit.com/uk/
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