Riyadh - The tax is expected to increase every year until 2020, when it will cap at 4,800 riyals per dependent annually.
On July 1, foreigners working in the private sector began paying a family tax of 100 riyals ($26.60/23.40 euros) per month for every minor or unemployed relative living in the kingdom, the Saudi general directorate of passports said in a statement.
An estimated 11 million foreigners work in the Saudi private sector, with 2.3 million of their dependents based in the kingdom, according to the Public Authority for Statistics.
The tax is expected to increase every year until 2020, when it will cap at 4,800 riyals ($1,280/1,126 euros) per dependent annually.
Saudi Arabia projects a government budget balance in 2020.
Saudi Arabia's ambitious "Vision 2030" plan, unveiled in April 2016, aims to broaden its investment base and diversify the economy.
The plan will also see the sale of nearly five per cent of state-owned Aramco -- the world's largest oil company reportedly worth between $2 trillion and $2.5 trillion.