Muslims have a duty to give 2.5% of their wealth to people in need every year. This is called 'Zakah', and it is one of the 'Five Pillars of Islam', the main rules of the religion. Muslims believe that everything they have comes from Allah, so they should help other people. Muslims can give money directly to the needy, but they usually put the money into the Zakah boxes in the mosque. Then the officers in the mosque arrange that the money goes to good causes.

No-one checks that Muslims give Zakah. It is between their conscience and Allah. Allah knows what everyone does.