I have a NFP client that I'd like to bring over to QBO. However, they require dual authorisations for ABA files. Can I still set up Bank feeds and ABA files?

It's nice to see you here today, @elingbookkeeping. Yes, you can still set up Bank Feeds and ABA files for your NFP client. I've got the steps to achieve your goal. 

For bank feeds, you'll first have to connect the bank account in the program. Just make sure to use the bank's URL when connecting it. Let me guide you how. 

1. Go to the Banking or Transactions menu. 
2. Choose Connect or Add account.
3. In the Let’s get a picture of your profits window, copy and paste the bank's URL in the Enter your bank name or URL search box. 
4. Enter the username and password you use for your bank's website. Follow the onscreen instructions if your bank requires additional security steps.
5. Choose the account the type of account you're adding (savings, transaction, or credit card). 
6. Select the date range for the download. 
7. Click Connect.

For more information, go through this article: Connect Bank and Credit Card Accounts to QuickBooks Online (QBO). 

If this client is your supplier, you can enable batch payments for your bank. I'll guide you how. 

1. Go to the Gear (Settings) icon at the upper right.
2. Select Chart of Accounts.
3. Locate your bank account.
4. Choose Edit in the Action column drop-down. 
5. Check the box I create batch payments for this account.
6. Fill in the relevant information for your bank.
7. Click Save and Close.

Then, enter an expense and create a batch payment file (.ABA). For detailed steps, check out this article: How To Enable Batch Payments or Create ABA Files.

However, if you're paying employees from this NFP organisation, you can set up the ABA settings for your business by performing the steps below. 

1. Go to Employees from the left menu. 
2. Select Payroll Settings.
3. Choose Payment Files under Business Settings. 
4. Click Add.
5. Enter the required details.
6. Hit Save. 

For your reference, visit this article: Set Up and Create ABA File in QuickBooks Payroll. This link also contains more details about the purpose of each ABA setting and how to create its files after you finalised a pay run. 

I'll be right here to help if you need further assistance. Have a great day, @elingbookkeeping.