When is a child held accountable for his sins and good deeds?

The sins committed by a child before reaching puberty are not recorded against him, as the Prophet, peace and blessings be upon him, said: "The pen has been lifted from three: from the sleeper until he awakens, from the child until he reaches puberty, and from the insane person until he regains his sanity." His family must prevent him from forbidden acts and train him in obligatory duties such as prayer. His good deeds are recorded for him, but his bad deeds are not. Once he reaches puberty, he will be held accountable for all his actions like an adult.