The Best Start Grant school age payment provides financial support for families who get tax credits and have a child born between March 1, 2016 and February 28, 2017.
Applications for the £250 payment, designed to help with the costs of preparing for school, will run until February 28, 2022.
It is one of five family payments offered by Social Security Scotland.
Social security minister Ben Macpherson said: “The Scottish Government is working hard to tackle poverty and to create a fairer society, with the powers and resources that we have.
“As part of this, we are set to increase our best start foods payments within the first 100 days of this new term of government and we are determined to make sure families with young children get all the financial help that is available.
“We are providing support worth about £5,000 by the time a child turns six through our Best Start Grant, best start foods and the Scottish child payment.
“People can apply for these payments on one simple, straightforward form – and I urge all those who are eligible to make sure they apply by visiting mygov.scot/beststart or calling 0800 182 2222.”
He added: “Access to financial support is important and we want people get the money they are entitled to.
“So, please check if you’re eligible and, if so, make sure to apply – and let others know too, so that together we can help build a fairer society here in Scotland.”