10 minutes. According to the information of official website, State Taxation Administration of The People's Republic of China, the system will give feedback within 10 minutes after completing the supplementary reporting operation at the tax counter. Please be patient. Supplementary declaration generally means that taxpayers fail to file tax returns after the tax return period, and make supplementary declarations at a later stage. Tax declaration refers to the legal act of taxpayers submitting written reports to tax authorities on tax matters in accordance with the time limit and contents stipulated in the tax law.