Most people borrow money to purchase an investment property. When borrowing money from the bank for your property, your bank most likely will charge you some fees for the privilege. 

These fees, or tax purposes, are considered borrowing costs.  Borrowing costs are:

• Application Fees
• Property Valuation Fees
• Lenders Mortgage Insurance
• Any other bank fee they like to charge

Borrowing costs deductibility has its own specific rules. They are not immediately deductible.  You will need to add up all these costs, the deduction is claimed over 5 years or the length of the loan.  Similar to depreciation, however, it's called amortisation. 

As a rough estimate, consider 20% of the borrowing costs are deductible per year.