Hi there,
It's important that you're able to record your corporate tax installments in QuickBooks Online. Since this is done outside of the QuickBooks environment, there's a few ways you can record these quarterly payments.
Here are the options:
1. Set up a CRA Income Tax vendor/supplier and book payments to the Accounts Payable under that name. Then, post the income tax as a bill.
2. Create an IncomeTax Installments account as a 'current asset'. Next, post installments here, and later transfer to the tax bill.
3. Create an Income Tax Due account under current liabilities and post both installments and the tax bill there.
Here's a few resources to help you along the way:
How to create a new parent account or sub-account - https://quickbooks.intuit.com/community/Reports-and-Accounting/How-to-create-a-new-parent-account-or...
How to enter and pay bills - https://quickbooks.intuit.com/community/Manage-vendors-and-expenses/How-to-enter-and-pay-bills/m-p/2...
If you've got any other questions, please let me know. I'm happy to help.
Cheers!