Further tax for unregistered buyers

Why a further tax amount is proposed on some lines.

When the buyer is unregistered for sales tax, further tax generally applies to taxable supplies of goods. The editor proposes it from your company's further tax rate when the buyer is unregistered; you can adjust the amount. Services and exempt or zero-rated supplies are not charged further tax by default. Check the rules that apply to your supplies.

Further tax for unregistered buyers | FBR Cloud