according to article 13 of State Taxation Administration of The People's Republic of China order No.16 of the measures for the administration of periodic fixed tax collection for individual industrial and commercial households

, a fixed-term fixed-income household shall handle relevant tax matters with the tax authorities under the following circumstances:?

(1) after comparing the quota with the invoice amount or the data recorded by the fiscal cash register, the tax payable for the business amount and income exceeding the quota;

therefore, for the self-employed individuals who are subject to regular fixed tax collection and management, if the fixed amount exceeds the invoiced amount, there is no need to pay back the tax; if the fixed amount is less than the invoiced amount, the tax should be paid back for the difference.