If it is necessary to identify the authenticity of handwriting, a judicial authentication institution shall be entrusted for identification. At the time of identification, it is necessary to provide the original of the identified sample and the original handwriting of the writer (that is, the writer specified in the identification sample) for comparison. The appraisal institution will confirm whether the identified sample is written by the writer through appraisal, and the authenticity of the handwriting can be judged according to the appraisal conclusion of the appraisal institution.

The principle of handwriting identification is that everyone's handwriting, like fingerprints, has its own inherent characteristics. Through the professional appraisal of the appraisal institution, it can be distinguished whether it is written by the same person.