Required.

1. If the appraisal report response letter is feedback or supplementary explanations for the appraisal report, it is best to be signed or stamped by the appraiser personally to express confirmation and responsibility for the content of the reply.

2. In some cases, the appraiser and the appraisal agency need to stamp it at the same time to ensure the validity and legality of the response letter.

3. Specific requirements vary depending on factors such as the type, purpose and relevant regulations of the assessment report.