A return is a declaration of transactions that took place during a particular period for purposes of ascertaining the tax position for that period.
All persons with income exceeding 2,820,000 a year, save for employees who earn income from only employment and with one employer.
You can apply for an extension to seek permission to file a return late however the extension cannot exceed an aggregate of 90 days. This extension shall not change the due date of payment of tax due for that period.
All the information required to file that particular return. E.g. for VAT, you need all purchase and Expenses and Sales (Including all taxable and exempt sales) transactions. Including those transactions where VAT has not been charged or incurred.
NB: Currently all transactions for input and output tax should be bearing FDNs from EFRIS.