How do I write a purchse order to my vendor?

Hello Penny!

Purchase Order is a non-posting transaction is available in the QuickBooks Online Plus version. If you have a different plan, we need to upgrade to have this feature. Here's how:

1. Click on the Gear icon.
2. Select Account and Settings.
3. In the Billing & Subscription section, click on the upgrade link. 
4. Confirm the new plan.

Otherwise, activate this feature from the company settings:  

1. Click on the Gear icon.
2. Select Account and Settings.
3. In the Expenses section, check the Use purchase orders box.
4. Click on Save.

Additional notes on how to create this form is here in this link: Create purchase orders in QuickBooks Online

We'll gladly help you if you have any questions about posting or running reports about Purchase Orders.