Revenue has been urged to set up an online tax calculator for workers on the Temporary Wage Subsidy Scheme.
Sinn Féin's spokesperson on Finance Pearse Doherty says a tax calculator would help provide clarity to PAYE workers, many of whom could face a tax liability at the end of the year.
Revenue has said that this liability will be offset against any unused tax credits for 2020.
Mr Doherty said that almost 568,000 workers have received payments through the Wage Subsidy Scheme since it was put in place.
"These payments are subject to income tax and to USC. Since this tax is not being paid in real-time, Revenue has said that these workers will be liable for tax by way of review at the end of the year," he said.
"Revenue has said that this liability will be offset against any unused tax credits for 2020, but for a worker receiving subsidy payments of €410 per week for twenty-two weeks, they are likely to have a tax liability in excess of €1,900, but unused tax credits of less than €1,400," he added.
He said that workers on the scheme need certainty in relation to their total tax liability and how it will be collected.
Workers do not know whether they will be required to make a lump sum payment at the end of the year, according to Mr Doherty, who said that any tax liability in excess of unused tax credits should be spread out over a sufficient length of time to provide certainty to workers.