How can I add PO# on the invoice

You can update your Sales form content and add a Custom field, tamratjanitorial. This way, you'll be able to input the PO numbers and monitor your sales transactions.

1. Go to the Gear icon.
2. Select Account and Settings.
3. Go to the Sales menu.
4. Click anywhere in the Sales form content section.
5. Enter the name of the custom field (e.g. PO#), then click the box under Internal.
6. Select Save, then Done.

I've attached screenshots below for your reference.

Moreover, you can also set your own numbering preference by turning on the Custom transaction numbers feature. This adds an Invoice no. field where you can enter any number or letter format you want. For the detailed steps, kindly refer to t his article: How to change the invoice number on sales forms.

You can also personalize your sales forms and add the information that matters to your business. The Custom form styles feature will let you create attractive, professional-looking invoices, estimates, and sales receipts. For the step-by-step guide, you can refer to this article: Customize invoices, estimates, and sales receipts in QuickBooks Online.

Please let me know if you have other concerns. I'm just around to help.