REVENUE MEMORANDUM ORDER NO. 4-2011 issued on February 7, 2011 prescribes the following policies and guidelines in the audit of Taxable Years 2009 and 2010 tax returns by the Revenue District Offices: a. All taxpayers are considered as possible candidates for audit. b. Priority shall be given to the following taxpayers who render professional services: • Lawyers; • Doctors; • Engineers; • Accountants; and • Other Professionals. c. Last Priority status for Income Tax audit shall be accorded to those taxpayers with an effective Income Tax rate of eighteen percent (18%) (Gross Income X 18%). An exception to the Last Priority status shall be those taxpayers where there are findings/suspicions of under-declaration of sales/revenues.