In May 2017, the issuance of the Measures on Regulating Professional Tax Services (Provisional) marked a significant innovation and breakthrough in the regulation of professional tax services by the STA. The professional tax service industry was thus subject to market competition with the STA taking effective measures to streamline administration, delegate powers to lower level tax authorities and abolish unnecessary approvals. In the meantime, the STA has also innovated regulation through interim and post-event supervision, and highlighted quality service to better serve taxpayers and tax service professionals. In 2018 and 2017, the Administrative Measures on Credit Rating of Professional Tax Services (Provisional) and the Guidelines on Credit Scoring Indices and Credit Rating for Tax Service Professionals were issued to further improve the credit system of the professional tax service industry. In 2019, the STA issued the Notice on Related Issues Concerning the Improvement of Professional Tax Service Regulatory System which further streamlined, revised and improved such mechanism as professional tax service data collection, credit re-rating and inquiry.