How do you allocate part of a PO to a supplier invoice?

Hello there, @richard-lill-lio.

You'll have to adjust the quantity or amount for each line item to allocate parts of a purchase order (PO) to your supplier invoice so you can keep your expense transactions accurate in QuickBooks Online (QBO).

When you've received only part of a PO, you can add just those parts to a bill or expense. This lets you link multiple transactions to the same (single) PO. Then, QuickBooks closes it when all its quantities are added to bills, expenses, or checks. To do this, here's how:

1. Go to the + New button.
2. Select Expense, Check, or Bill. 
3. From the Payee ▼ dropdown, select the vendor. This opens a window with their open purchase orders.
4. Select Add for the correct purchase order to add the items. They appear in the Item details section.
5. Adjust the quantity or amount for each line item to reflect the portion you received or plan to pay for.
6. Select Save and close.

You can read this article for the complete guide to adding an accepted PO to a supplier transaction in QBO: Add purchase orders to expenses, bills, or cheques in QuickBooks Online.

Also, you may want to check out this article as your reference to guide you when to enter bills and record cheques or expenses in QBO: Learn the difference between bills, cheques, and expenses in QuickBooks Online.

If there's anything else you need or questions about allocating POs and managing expenses in QBO, please don't hesitate to comment below. I'm always ready to help. Take care, and have a great day, @richard-lill-lio.