Revenue has said that they are aware of "intermittent issues" with their online services as thousands of PAYE workers have logged on to check if they have received a tax bill in relation to the Temporary Wage Subsidy Scheme (TWSS) and the Pandemic Unemployment Payment (PUP).
The payments were not taxed in real-time and instead are liable to income tax and universal social charge (USC) at the end of the year.
In a Tweet, they said: "For some customers performance is slow and for others the service is unavailable. Our technical teams are currently working to resolve the issues."
Revenue has said over 400,000 workers in receipt of PUP or the wage top-up will begin to receive tax bills this morning.
Employees will be given the option to pay partially or in full. People are not expected to pay in full, instead, Revenue may reduce a person's tax credits starting in 2022.
The preliminary end of year statements for tax liability come as provisional statistics published by Revenue show less than half of workers at 43% or 988,100 were charged the correct amount of tax and USC.
Over 600,000 or 27% of workers underpaid tax and USC in 2020 to the amount of €458m while 30% or 706,100 workers overpaid tax and USC to an amount of €436m.
Revenue has issued assurances that underpayments by workers will not be deducted immediately as this can cause financial hardship. A spokesman said that the amounts will be deducted interest-free over the next four years and will not begin until January 2022.
Speaking about the tax liabilities published this morning, Declan Rigney, head of Revenue’s Personal Division, said the end of year statement is only a provisional figure. He said the taxpayer can finalise this figure by completing an income tax return online.
“The Preliminary End of Year Statement is only a provisional tax position. An employee can finalise his or her tax position for 2020 by completing an income tax return online.
“This tax return will be pre-populated with the information shown on the Preliminary End of Year Statement which makes it relatively straight forward to complete and minimises the possibility of errors and omissions.
“Completing a tax return allows an employee to review the information presented and to claim additional tax credits, such as health expenses, or declare additional incomes, as appropriate.
“Once an employee submits his or her tax return, a Statement of Liability will issue shortly afterwards, setting out the final tax and USC position for the year,” said Mr Digney.
Workers will have access to their tax liability in the MyAccount portal of Revenue.ie
This week the government published figures to show over 398,000 people are in receipt of PUP after a return to Level 5 restrictions.
Workers in the hospitality, retail, and construction sectors are among the highest recipients.