You should pay and file your tax returns electronically using the Revenue Online Service (ROS). You can benefit from an extension to existing deadlines for paying and filing returns if you pay and file using ROS.
The majority of Revenue’s business customers are legally obliged to both efile and epay. If you do not use ROS to pay and file, you may incur a penalty of €1,520 on each transaction.
You can find more information on mandatory efiling in the Starting a business section.