Legal analysis: it is ok to write a copy of the will to the heir. According to the relevant laws and regulations, a self-written will should be written, signed and marked with the year, month and day by the testator. As long as it does not violate the mandatory provisions of laws and administrative regulations, it can have corresponding legal effect according to law. Legal basis: Article 143 of the Civil Law of People's Republic of China (PRC) is valid for civil juristic acts that meet the following conditions: (1) The actor has corresponding capacity for civil conduct; (2) the meaning is true; (three) does not violate the mandatory provisions of laws and administrative regulations, and does not violate public order and good customs. Article 134 A self-made will shall be signed by the testator and marked with the year, month and day. Article 143 A will made by a person without or with limited capacity for civil conduct is invalid. A will must express the true meaning of the testator, and a will made by fraud or coercion is invalid. Forged wills are invalid. If the will is tampered with, the tampered contents are invalid.