The Revenue Department will give accounting firms a checklist for screening client tax filings to prevent understatement of profits and underpayment of corporate income tax.
The checklist will be used to determine whether tax calculations meet standards and to spot irregularities such as improperly booked expenses and sales, said director-general Prasong Poontaneat.
"Should we find anything unusual in the tax filings of 27 out of an accounting firm's 30 customers, we will backtrack to which company has been in charge of arranging such troubled tax filings and all customers of that firm will be inspected," Mr Prasong told a meeting this week of 700 representatives from accounting firms.
The stringent move comes at a time when the department is trying to narrow its revenue shortfall for fiscal 2014, which runs through the end of September.
Mr Prasong said Tuesday that the department would do its best to achieve the tax collection target of 1.89 trillion baht for fiscal 2014 and should not miss the target by more than 100 billion or 5-6%.
The Revenue Department plans to join forces with the Business Development Department and the Federation of Accounting Professions to control accounting quality.
Mr Prasong said his department will amend rules and regulations to authorise the department's central units to double-check tax payments inspected by officials of the department's offices to create a system of checks and balances.
The department has also floated the idea of hiring accounting firms to submit companies' tax filings through an online system to save cost and time spent filling out such information.
Mr Prasong repeatedly said the department will amend the law to make income contributed by non-juristic bodies of persons subject to personal income tax.