BAS Expense category I get error You have either selected a tax liability account on a transaction where it's not allowed, or haven't specified a tax rate along with it.

Hi Linda de Bie, 

Correct, the account you want to select for this work around is 'GST Liabilities Payable'. To answer your second question, also correct, as the journal acts as a mediator for the funds moving from the bank account to the GST account for BAS purposes, which is best to record the entry on the same day for reconciliation purposes. Once you select Save and Close, please check back on your Bank Feed for the option to Match the transaction to the journal entry. 

Please keep in mind that if you are using QuickBook's GST centre to lodge your BAS, you can record the payment there and match it to your bank feed rather than using a journal' work around, which you can see the steps here.

Let me know how you go, if you still feel like you're not getting anyway where you can always contact our support team here

Thanks, 

-Steven