Is it possible to automatically create a list of customers according to their payment method i.e Direct Debit / BACS etc

Yes, it's possible, @accounts403.

You can pull up the Sales by Customer Detail report and group it by payment method. 

Here's how:

1. In QuickBooks, go to the Reports menu.
2. Search for the Sales by Customer Detail, click the report to open.
3. Select the Customise button.
4. Under the Rows/Columns section, tap the Group by drop-down arrow and choose Payment method.
5. Hit Run report.

For more info about customising reports in QBO, please see this article: Customise reports in QuickBooks Online.

Also, to learn more about the latest product updates in QuickBooks Online, see our QuickBooks Blog page. This covers a wide range of topics that will help your business prosper.

 
Should you need anything else, don't hesitate to comment below. I'm always around to help if you have concerns about creating lists to show your desired data. Stay safe and take care always.