How should preliminary expenses be treated in the year they are incurred?

Written-off from securities premium entirely

Companies follow specific guidelines for accounting treatment of preliminary expenses and borrowing costs, such as discounts on debenture issuance, to ensure accurate financial reporting.
Preliminary Expenses: These expenses incurred during the company's establishment should be entirely written off in the same year they are incurred. The write-off process starts with utilizing the securities premium, if available, to cover these expenses. Any remaining balance is then written off from the statement of profit & loss.
Borrowing Costs: When the company issues debentures, any borrowing costs associated with the issuance, like discounts, should also be written off in the same year of debenture issuance.