Final answer:
Share issue costs reduce the net cash proceeds and should be deducted from paid-in capital - excess of par on the company's financial statements.
Step-by-step explanation:
Share issue costs refer to the expenses incurred when a company issues new shares, including legal, promotional, and accounting fees. These costs reduce the net cash proceeds from selling the shares and are accounted for in the company's financial statements. The appropriate treatment for share issue costs is to deduct them from paid-in capital - excess of par. This reflects the actual costs of issuing the shares and provides a transparent picture of the financial transaction to investors and other stakeholders.