When I want to do a new PO to a supplier I have previously sent a PO to, why does it pull through all the line items of the previous PO?

Hi there, @accounts-jups-co.

Allow me to share some details about the pre-fill feature in QuickBooks Online.

This happen when the auto-fill feature was turned on in your settings. When auto-recall is turned on, QuickBooks will automatically fill in the rest of the transaction with the details you've made when selecting a customer, vendor, or employee.

If you want to remove this feature, you may need to turn off this setting. Here's how:

1. Go to the Gear icon.
2. Select Account and Settings.
3. Click the Advanced tab.
4. Select the pencil icon in the Automation section.
5. Uncheck the box beside Pre-fill forms with previously entered content.
6. Click Save and Done.

I've added an article to know more about managing the recall setting: Bill created from purchase order has incorrect or higher amount.

You may consider checking this reference page for your future task about tracking your business transactions or financials: Run reports in QuickBooks Online. This also contains information on how you can set up general report preferences and how to customize them.

Please let me know if there's anything else you need help with. I'm just around to help. Take care!