All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
Jumu’ah Prayer requires a certain number of mature participants. The jurists differed in opinion over the minimum number required for a valid Friday prayer. According to the Shaafi'i and Ahmad Schools of jurisprudence, a number of forty people are required. Jaabir, may Allah be pleased with him, said: “According to the Sunnah, the Friday (Jumu’ah) prayer should be performed when there are forty or more people."
It was also said that four or twelve people are enough for the Friday (Jumu’ah) prayer.
For more benefit on the conditions for Friday prayer, please refer to Fataawa 82835, 82979, 356992, 117037 and 257203.
Allah knows best.