The law does not stipulate how many signatures are required for joint appeals. According to the provisions of the Civil Procedure Law, a party who refuses to accept the judgment of the local people's court of first instance has the right to appeal to the people's court at the next higher level within 15 days from the date when the judgment is served.

Conditions for joint prosecution: If the subject matter of litigation is the same and there are a large number of parties, the people's court may issue an announcement explaining the case and the claim, and notify the obligee to register with the people's court within a certain period of time. The obligee registered in the people's court may elect a representative to conduct litigation; If there is no elected representative, the people's court may appoint a representative with the right holder who participates in the registration. The litigation behavior of a representative is valid for the party he represents, but the representative must obtain the consent of the principal if he changes, gives up or acknowledges the litigation request of the other party and makes a settlement. The judgment and ruling made by the people's court shall be effective for all the right holders who participate in the registration. If the obligee who has not participated in the registration brings a lawsuit during the limitation period, the judgment or ruling shall apply.

The consolidated appeal is written like this:

1, the parties (that is, the basic information of the original and the defendant), indicating the natural situation;

2, the litigation request, specify the specific matters of the people's court to solve civil rights disputes according to law;

3, facts and reasons, to fully reflect the objective truth of the disputed facts, including the occurrence and process of the disputed facts and opinions, reasons and basis for solving the dispute;

4. Evidence part:

(1) List relevant documentary evidence, physical evidence and other relevant materials that can prove the truth;

(2) instruction certificate;

(3) Sources and reliable procedures of material evidence and other relevant materials;

(four) the contents of the witness's testimony and the name and address of the witness;

5. At the end of the complaint, if the party is a natural person, it must be signed by himself; If it is a legal person or other organization, it shall be signed by the legal representative or person in charge and stamped with the official seal of the unit.

I hope the above content can help you. Please consult a professional lawyer if you have any other questions.

Legal basis: People's Republic of China (PRC) Civil Procedure Law.

Article 164 If a party refuses to accept the judgment of first instance of a local people's court, he shall have the right to appeal to the people's court at the next higher level within 15 days from the date when the judgment is served. If a party refuses to accept the ruling of the local people's court of first instance, he has the right to appeal to the people's court at the next higher level within 10 days from the date when the ruling is served.

Article 165 An appeal shall be attached. The contents of the appeal shall include the names of the parties, legal persons, their legal representatives or other organizations, the names of the principal responsible persons, the names of the people's courts, the number of cases, and the petitions and reasons.