Tax is generated based on the zip code for the customer. So if you are creating an order with taxable products you will need to make sure that the zip code is correct on the shipping address. This will allow the system to populate the Tax Postal Code on the Order.
For tax to generate on a product added to a manual order, the following steps must be taken when creating the manual order:
1. Go to the contact record
2. On the left-hand navigation pane, go to Sales & Marketing -> Orders
3. Click Add New Order
4. Fill in the name
5. Fill in the Zip/Postal Code in the Ship To Address
6. Fill in any other required fields
7. Save the record.
Use the menu tiles to navigate from a Contact record to Orders.
*You can only edit active orders. If you want to edit a fulfilled order you will first need to unapply payment to activate it and then make your changes.