ACCORDING to the Bureau of Internal Revenue (BIR), the withholding tax system is 'considered an effective tool in the collection of taxes' as it 'encourages voluntary compliance,' 'reduces cost of collection effort,' 'prevents delinquencies and revenue loss,' and 'prevents [a] dry spell in the fiscal conditions of the government by providing revenues throughout the taxable year.'

In 2018, the BIR started circulating a list of 'Top Withholding Agents' or TWAs that are required to withhold taxes on purchases of goods and services. Additional lists continue to be posted, including those delisted by the bureau or those formerly listed as TWAs and are no longer required to withhold.