The supplier bill defaulted to Trade & Other payables account. I would like to be able to set it to other default account such as just Other payables as it non-trade.

The option to change the default Accounts Payable (A/P) in QuickBooks Online (QBO) is unavailable, @ubittohq. However, you can use a journal entry to record the bill in different A/P account. Let me explain further below.

In QuickBooks, you can set up multiple A/P accounts. However, your bills will automatically be posted to the default A/P. This account is the one created when you set up your company or the one you selected during conversion. Here's an article with more details: How to group Accounts Receivable or Accounts Payable account types in QuickBooks Online.

If you want your bills to be posted to a different A/P account, you can record the transaction using a journal entry instead of the bill feature. I'll guide you on how to do this.

Before you proceed, I recommend consulting your accountant to ensure the accuracy of your books.
 

1. Click on the + New button and select Journal entry.
2. On the first line, select an account from the Account field.
3. On the next line, select the other account you're moving money to or from. Depending on whether you entered a debit or credit on the first line, enter the same amount in the opposite column.
4. Check the amounts and ensure you enter the same amount in the Credit column on one line and the Debit column on the other. This ensures the accounts are in balance.
5. Enter information in the Memo section to document why you made the journal entry.
6. Select Save and close.
    

You can check out this article for additional reference: Create journal entries in QuickBooks Online.

Furthermore, you can run the Accounts Payable aging summary or Accounts Payable aging detail report to track your unpaid bills. Here's an article for guidance: Run a report in QuickBooks Online.

Please let me know by replying to this thread if you need clarification on managing Accounts payable and bills in QuickBooks. I'll be glad to assist you.