You can set up the tax option for purchase cost in a purchase order easily in Hike.
You would first need to confirm whether the product cost on the product page, as shown below, is the tax-inclusive or tax-exclusive one.
To set this up, please navigate to:
Store setup > General > Review the option "Item costs defined on product page are tax-inclusive cost prices" in the section of General Rules.
The option is ticked by default, which means Hike will take the cost as a tax-inclusive one. You can change it as per your requirements.
Then, when you create a purchase order, the cost on the product page will be input into the tax-exclusive or tax-inclusive field as per your settings. Both fields are editable, so you have the flexibility to change either based on whether your supplier is providing the tax-exclusive quote or the tax-inclusive one. After editing one, the system will calculate the value of the other one automatically.
When you will create a purchase order, the by default Tax will be shown as per the Supplier’s Tax. Please check the screebshot below for reference.