Businesses which import items from another country, for example a Canadian business importing books from the USA, often pay the vendor directly for the item and then must pay customs separately for the border taxes/duties.
Since you have already paid for the item already, the question is: how should you record the sales taxes charged at the border in Kashoo?
You should receive an invoice from customs, or from your customs broker, with the fees and taxes on it.
First enter an expense or bill as usual and record the service charges from the customs broker (if any) in their own expense account, say "Customs Broker Fees."
Next add a line item for the item or items you are charged duties on as if you are buying them; however, instead of entering the original price, set the price to zero. In the tax column (where you would normally select a tax percentage) type in the amount of tax; for example "27.71 GST". This way you have entered the fixed tax amount and that the tax you paid is categorized correctly in your tax reports when you file your sales taxes.
Time-saver: if GST is the first tax in your list, you can type the amount and the software will choose GST for you. For example, entering "27.71" alone for a Canadian business is automatically expanded into "27.71 GST".
Click "Add" to enter the bill into the system. Your taxes and remittances reports should be updated appropriately.