You can apply for a power of attorney. If the purchaser is unable to sign due to special circumstances, he may entrust other adult citizens to sign and seal in writing. The signature of the agent is valid as long as there is written authorization from the buyer. Legal basis: Article 15 of the Measures for Housing Registration. To apply for housing registration, the applicant shall use Chinese name or title. If the original submitted by the applicant is in a foreign language, a Chinese translation shall be provided. Where an agent is entrusted to apply for housing registration, the agent shall submit the power of attorney and identity certificate. Where an overseas applicant entrusts an agent to apply for housing registration, the power of attorney shall be notarized or authenticated in accordance with the relevant provisions of the state.