Is there a way to add a custom column in my purchase orders?Something like a notes or tag field for each line.

Let me share the details about customizing your purchase orders in QuickBooks Online, Desmond.

In QuickBooks, adding a column for notes when creating purchase orders is currently not available. However, you can utilize the custom field feature to create additional fields tailored to your specific needs, where you can input relevant information or comments.

Here's how:

1. Go to the Gear icon, then click Custom fields.
   
2. Hit the Add field and enter a name for your field.
   
3. Select Data type and choose Supplier.
4. Check the Purchase Order box and turn on the Print on form if you want this field to show when printing your purchase order.
5. Once done, click Save.
   

For comprehensive information about custom fields, you can visit this article: Use custom fields for suppliers and expenses in QuickBooks Online Advanced.

If you want to accept purchase orders to a transaction for your vendor, check out this article: Add purchase orders to expenses, bills, or checks in QuickBooks Online.

I'll keep this thread open if you have other concerns or questions about customizing purchase orders in QuickBooks Online. The Community has your back always!