Senate has 104 members elected for six years, but half of them retire every three years at completion of term and new Senators are elected indirectly by provincial and national assemblies through proportional representation.
According to Election Commission of Pakistan (ECP), polling will be held at the four provincial and the national assembly buildings. It will start at 9 am and will continue till 4 pm.
The 52 Senators retiring this month were elected in 2012. The other 52 were elected in 2015 and will serve until 2021.
In case of non-compliance the controlling officer will cancel the ballot paper of such persons.
It was also decided that all controlling officers will have powers of full magistrate and they can suspend the electoral process by bringing such elements to ECP's notice in case of irregularity.
The officials said that 46 senators will be elected by the four provincial assemblies, 2 by the National Assembly and 4 by the lawmakers from tribal areas.