MANILA - The Bureau of Internal Revenue (BIR) reiterated on Wednesday that business taxpayers seeking income tax deductions for losses incurred due to typhoons "Ondoy" and "Pepeng" should show proof of damage to property.

According to the tax agency, some business owners applying for deductions have not been submitting the necessary documents.

BIR's Revenue Memorandum Order 31-2009 requires taxpayers whose enterprises have been devastated by the back-to-back typhoons need to submit a sworn declaration of loss and other documents to substantiate their proof of loss.

Documents must be filed within 45 days after the date of the event.

The BIR said the sworn declaration must be supported by the taxpayer's financial statement for the year and copies of insurance policies.

Applicants should also submit photographs of their affected properties taken before and after the typhoons to show the extent of damage. The properties must be those actually used in the business enterprise and included in its accounting records and financial statements.

There should also be documentary evidence for determining the cost or valuation of the damaged properties such as cancelled checks, vouchers and receipts.

The BIR said the amount of loss compensated by insurance coverage should not be claimed as a deductible loss.

The agency issued the additional guidelines after announcing last week that taxpayers may claim income tax deductions for losses brought about by the two typhoons.

Massive damage caused by the recent typhoons to the Philippines have made the BIR lose hope in meeting its collection target of P798.5 billion for 2009.

"From all indications, because of these developments, we may not be in the position to attain the (target)," said BIR Senior Deputy Commissioner Joel Tan-Torres.