If you are self-employed and do not meet the threshold of the local IRS, this piece of IRS will be ignored, so there is no problem without tax registration. But the law says it must be dealt with. Please refer to the following legal provisions:

Tax collection and management law

Chapter V Legal Liability Article 60 If a taxpayer commits any of the following acts, the tax authorities shall order it to make corrections within a time limit and may impose a fine of less than 2,000 yuan; If the circumstances are serious, a fine of not less than 2,000 yuan but not more than 10,000 yuan shall be imposed: (1) Failing to go through tax registration, change registration or cancellation registration within the prescribed time limit;