You need to use a 3rd party inventory management app as the hub.

I appreciate your efforts to make the MPN and SKU appear in the Purchase Order (PO) and Bill, @jhj2. While adding the MPN directly to the items is unavailable, allow me to provide an alternative solution by creating a custom field.

To display the SKU in the PO and bill, please make sure to turn on the Show SKU column in the Account and settings. See the picture below for visual reference.

Here's a before and after turning on the SKU column.

Let's create a custom field for the MPN to add it to the PO and bill. This will allow us to enter it manually.

I'll show you how:

1. Go to the Gear icon, then select the Custom fields.
2. Click the Add custom field.
   
3. Enter MPN in the Name field, then select Text and number from the Data type dropdown.
4. Tick the Purchase Order and Bill.
5. Turn on Print on form (optional).
6. Select Save.
   

Please refer to the picture below for a visual reference. It shows where you can input the MPN and SKU in the Purchase Order and Bill after creating a custom field.

You can also input the MPN in the description field under the DESCRIPTION column of the PO and Bill.

I would love to introduce you to the QuickBooks Live Expert Assisted team. They're a group of experienced experts ready to help you smooth out your financial operations that fit your business needs.

I'll add some helpful articles that can guide you through running a purchase order report and emailing your bills to QuickBooks:

• PO reports
• Forward Bill

Please revisit this thread if you find other questions, @jhj2. We're always here in the Community space to assist you. Have a great day.